Hi, after having issues with WSUS server content getting to huge I followed these instruction to reset the updates: http://blogs.technet.com/b/gborger/archive/2009/02/27/what-to-do-when-your-wsuscontent-folder-grows-too-large.aspx

Now WSUS has re-downloaded all necesery updates, from WSUS (3.2.7600.226) I see that my computer needs 11 more updates, I check update from computer (Update Agent 7.6.7600.256) then it does not see any new update? And Windowsupdate.log confirms that query was indeed succeful but did not return any results:

2015-02-20	10:26:35:720	 936	2b18	AU	Triggering AU detection through DetectNow API
2015-02-20	10:26:35:720	 936	2b18	AU	Triggering Online detection (interactive)
2015-02-20	10:26:35:720	 936	12cc	AU	#############
2015-02-20	10:26:35:720	 936	12cc	AU	## START ##  AU: Search for updates
2015-02-20	10:26:35:720	 936	12cc	AU	#########
2015-02-20	10:26:35:722	 936	12cc	AU	<<## SUBMITTED ## AU: Search for updates [CallId = {13FAC886-1E20-4170-BE60-787B20C53FAF}]
2015-02-20	10:26:35:723	 936	20c0	Agent	*************
2015-02-20	10:26:35:723	 936	20c0	Agent	** START **  Agent: Finding updates [CallerId = AutomaticUpdates]
2015-02-20	10:26:35:723	 936	20c0	Agent	*********
2015-02-20	10:26:35:723	 936	20c0	Agent	  * Online = Yes; Ignore download priority = No
2015-02-20	10:26:35:723	 936	20c0	Agent	  * Criteria = "IsInstalled=0 and DeploymentAction='Installation' or IsPresent=1 and DeploymentAction='Uninstallation' or IsInstalled=1 and DeploymentAction='Installation' and RebootRequired=1 or IsInstalled=0 and DeploymentAction='Uninstallation' and RebootRequired=1"
2015-02-20	10:26:35:723	 936	20c0	Agent	  * ServiceID = {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7} Managed
2015-02-20	10:26:35:723	 936	20c0	Agent	  * Search Scope = {Machine}
2015-02-20	10:26:35:780	 936	20c0	Setup	Checking for agent SelfUpdate
2015-02-20	10:26:35:781	 936	20c0	Setup	Client version: Core: 7.6.7600.256  Aux: 7.6.7600.256
2015-02-20	10:26:35:781	 936	20c0	Misc	Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab:
2015-02-20	10:26:35:788	 936	20c0	Misc	 Microsoft signed: Yes
2015-02-20	10:26:35:798	 936	20c0	Misc	Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab:
2015-02-20	10:26:35:804	 936	20c0	Misc	 Microsoft signed: Yes
2015-02-20	10:26:35:808	 936	20c0	Misc	Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wsus3setup.cab:
2015-02-20	10:26:35:815	 936	20c0	Misc	 Microsoft signed: Yes
2015-02-20	10:26:35:824	 936	20c0	Misc	Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wsus3setup.cab:
2015-02-20	10:26:35:830	 936	20c0	Misc	 Microsoft signed: Yes
2015-02-20	10:26:35:852	 936	20c0	Setup	Determining whether a new setup handler needs to be downloaded
2015-02-20	10:26:35:852	 936	20c0	Setup	SelfUpdate handler is not found.  It will be downloaded
2015-02-20	10:26:35:852	 936	20c0	Setup	Evaluating applicability of setup package "WUClient-SelfUpdate-ActiveX~31bf3856ad364e35~amd64~~7.6.7600.256"
2015-02-20	10:26:35:855	 936	20c0	Setup	Setup package "WUClient-SelfUpdate-ActiveX~31bf3856ad364e35~amd64~~7.6.7600.256" is already installed.
2015-02-20	10:26:35:856	 936	20c0	Setup	Evaluating applicability of setup package "WUClient-SelfUpdate-Aux-TopLevel~31bf3856ad364e35~amd64~~7.6.7600.256"
2015-02-20	10:26:35:876	 936	20c0	Setup	Setup package "WUClient-SelfUpdate-Aux-TopLevel~31bf3856ad364e35~amd64~~7.6.7600.256" is already installed.
2015-02-20	10:26:35:877	 936	20c0	Setup	Evaluating applicability of setup package "WUClient-SelfUpdate-Core-TopLevel~31bf3856ad364e35~amd64~~7.6.7600.256"
2015-02-20	10:26:35:895	 936	20c0	Setup	Setup package "WUClient-SelfUpdate-Core-TopLevel~31bf3856ad364e35~amd64~~7.6.7600.256" is already installed.
2015-02-20	10:26:35:895	 936	20c0	Setup	SelfUpdate check completed.  SelfUpdate is NOT required.
2015-02-20	10:26:38:386	 936	20c0	PT	+++++++++++  PT: Synchronizing server updates  +++++++++++
2015-02-20	10:26:38:386	 936	20c0	PT	  + ServiceId = {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7}, Server URL = http://<my server: port>/ClientWebService/client.asmx
2015-02-20	10:26:58:657	 936	20c0	PT	+++++++++++  PT: Synchronizing extended update info  +++++++++++
2015-02-20	10:26:58:657	 936	20c0	PT	  + ServiceId = {3DA21691-E39D-4DA6-8A4B-B43877BCB1B7}, Server URL = http://<my server: port>/ClientWebService/client.asmx
2015-02-20	10:26:59:644	 936	20c0	Agent	  * Found 0 updates and 87 categories in search; evaluated appl. rules of 6621 out of 10349 deployed entities
2015-02-20	10:26:59:645	 936	20c0	Agent	*********
2015-02-20	10:26:59:645	 936	20c0	Agent	**  END  **  Agent: Finding updates [CallerId = AutomaticUpdates]
2015-02-20	10:26:59:645	 936	20c0	Agent	*************
2015-02-20	10:26:59:695	 936	2990	AU	>>##  RESUMED  ## AU: Search for updates [CallId = {13FAC886-1E20-4170-BE60-787B20C53FAF}]
2015-02-20	10:26:59:695	 936	2990	AU	  # 0 updates detected
2015-02-20	10:26:59:695	 936	2990	AU	#########
2015-02-20	10:26:59:695	 936	2990	AU	##  END  ##  AU: Search for updates [CallId = {13FAC886-1E20-4170-BE60-787B20C53FAF}]
2015-02-20	10:26:59:695	 936	2990	AU	#############
2015-02-20	10:26:59:695	 936	2990	AU	Successfully wrote event for AU health state:0
2015-02-20	10:26:59:695	 936	2990	AU	Featured notifications is disabled.
2015-02-20	10:26:59:696	 936	2990	AU	AU setting next detection timeout to 2015-02-21 04:59:38
2015-02-20	10:26:59:696	 936	2990	AU	Setting AU scheduled install time to 2015-02-20 10:00:00
2015-02-20	10:26:59:696	 936	2990	AU	Successfully wrote event for AU health state:0
2015-02-20	10:26:59:696	 936	2990	AU	Successfully wrote event for AU health state:0
2015-02-20	10:27:04:644	 936	20c0	Report	REPORT EVENT: {59508799-0F87-4B7B-B5B3-3618921B0A0C}	2015-02-20 10:26:59:644+0200	1	147	101	{00000000-0000-0000-0000-000000000000}	0	0	AutomaticUpdates	Success	Software Synchronization	Windows Update Client successfully detected 0 updates.
2015-02-20	10:27:04:644	 936	20c0	Report	REPORT EVENT: {F94114C0-3E2A-4592-9D49-116CE4A38A29}	2015-02-20 10:26:59:645+0200	1	156	101	{00000000-0000-0000-0000-000000000000}	0	0	AutomaticUpdates	Success	Pre-Deployment Check	Reporting client status.
2015-02-20	10:27:04:646	 936	20c0	Report	CWERReporter finishing event handling. (00000000)

I have configured WSUS so that it stored updates locally on server (only when approved) and it shall download express installation files.

Other thing that bother me is that even though GPO specifies not to allow automatic restart for Windows Update for some updates it still does reboot windows with 15 minutes countdown with no option to postpone it (if user is not at the desk then he/she shall loose all open matters). 

In regards to the 11 updates needed. This will be based on updates the WSUS is aware of. Updates will not be applied until the update has been downloaded in its entirety to the WSUS server and until that time you will experience reporting similar to your description.

As you mentioned you have cleared the WSUS content and reset with WSUSUtil, the server is aware of updates that are configured to download as specified in products and classifications and updates that are approved as this exists within the WSUS DB however the actually content no longer exists and will therefore start downloading. Depending on what you have selected this could take a considerable amount of time and delay updates being applied.

The easiest way to confirm whether this is the cause is to check WSUS is still downloading needed files. This is displayed below download "status" in the details pane after selecting the server node in the WSUS console.

If this is the case I would suggest waiting until all downloads are complete and evaluate the situation again.

If you need an imediete answer you can identify the updates needed in the report and then check the relevant update node. Updates that are still being downloaded will display an icon to the left of the download title.

Regarding client behaviour this is almost certainly a GPO configuration possibly even a conflict with another GPO. If you are sure on your individual policies. Id suggest running the following from the client machine

gpresult /h GPreport.html

review the output to confirm the "winning" GPO that is applying the settings and check the configuration.

I hope this helps. Good luck :-)

Also to add. The original concern was with WSUSContent bloat. After re reading the OP is see you have opted to use express installation. In your scenario this will be a contributing factor to both the size of your downloaded updates and the time it takes to download them.

I'm sure your aware of the benefit of express installation files however given your scenario you may need to way up the pro and cons