On a general basis (not F# development) I've gravitated to using Visual Studio most of the time.

SharpDevelop is faster to load but I find Visual Studio more productive overall (I do have additional development tools and some custom work which make it hard to beat). Having said that I have fired up SD to convert code and Boo looks interesting. I also found that SD once messed up some solutions for VS 2005 which caused me extra work, so I'm very careful how I use SD.

I'm sure there's more to it but those are the issues I can think of immediately.

The project system is based on msbuild so that means you can build the project with either SharpDevelop or msbuild, which is great for automatic builds. It should also mean the references between C# and F# projects are easier (but I haven't tested this). I'm also hoping to add support of reording files and generation and management of interface files before too long.

Having said that the vusial studio integrations big advantage is the back ground type checking and the auto-completion, and I have no imedaite plans to implement either of those.

I see the SharpDevelop intergration being more for existing SharpDevelop users who want to use F# rather something that could replace visual studio.

It's also important to note that the beta1 build is still quite buggy, I hoping to get some of the issues sorted out soon.