I’m using ASP.NET membership provider to manage ASP.NET users and roles. I’m using IIS 7. I can say just one thing: use IIS 7!!! You can manage the whole ASP.NET membership task from IIS7 MMC.
The best part: it gives much more information about errors compared to ASP.NET Configuration web-based configuration editor. I’ve extended the schema with own tables and I made a wrong constraint so I couldn’t create new users. I got a generic error message in web-based configuration editor tool. I got a specific error message in IIS 7. I couldn’t have traced back the error to the database without IIS 7 (or just with huge effort).