They’re great if you’re into the development aspect of web hosting, i.e. a SQL Server database and ASP.NET pages and stuff like that. If you don’t know what I’m talking about, then you should probably go with someone else as you’ll be paying for something you won’t use.
However, if you’re into these Microsoft web technologies, then hostmysite.com is pretty awesome. Their service is really good – you can always get someone on the phone very quickly. I’ve been happy with them.