Hi,
Visual studio is more like developer tools whereas SharePoint Designer is more targeted for Power Users. There's few points you can consider:
- For simple workflow you can use SharePoint Designer. But if your workflow has integration with other system or has complex logic (for example, get data from SAP for the user, calculate leave etc.) then you better use Visual Studio to develop the workflow.
- Visual Studio requires developer experience (C#, JavaScript etc.) and if you are a developer you would prefer Visual Studio. But if you are PowerUser, then definitely you can use SharePoint Designer.
- Power User provides rapid/quick solution in an organization - like using InfoPath, SharePoint Designer, Access etc. However complex solution requires developer involvements. So you can compare your requirements/situation and decide accordingly.
Long story short, Visual Studio is for more developer-like and for complex workflows as per my opinion. I'm a SharePoint developer/architect and never developed SharePoint Designer workflow. Whereas PowerUsers will prefer SharePoint Designer as they will
not work code in Visual Studio.
Simple strategy you can follow, can the workflow be developed with SharePoint Designer, if yes then go for it. Otherwise look for alternatives - Visual Studio, Nintex etc.