Mono does lag behind the main .NET stack, but the gap is getting smaller because MS is opening things up. For example, MS released the ASP.NET MVC source under a license that allowed the Mono folks to basically just drop it in with few modifications so it worked with Mono on the day it was released to the public.
Beyond that, it's kind of a pain in the ass to do a quick edit of a file to fix something when you're on the road if you don't have all of your tools available.
If this is a priority for you, you can use ASP.NET Web site projects and edit live versions without recompiling/redeploying (for the most part). Web site projects are Webforms-only though, no MVC. However, I think not having the ability to make ad-hoc changes to production code is a feature ;)
I think not having the ability to make ad-hoc changes to production code is a feature
True, but in my defense we are a continuous integration / almost continuous deployment shop ;). As soon as commits are made our tests get run, the product gets built and configured and automatically staged. Usually what happens is I get a phone call that there's a problem, fix it and then let someone test it and push the big red "RELEASE" button.
Beyond that, it's kind of a pain in the ass to do a quick edit of a file to fix something when you're on the road if you don't have all of your tools available.
If this is a priority for you, you can use ASP.NET Web site projects and edit live versions without recompiling/redeploying (for the most part). Web site projects are Webforms-only though, no MVC. However, I think not having the ability to make ad-hoc changes to production code is a feature ;)