AlexarahX: I haven't used VS, so I can't compare them.  However, I've never found MonoDevelop to be an issue for my uses.

If you're intending to just work with UFE, MonoDevelop should be good enough for your needs.

JS and C# aren't that much different, it's mostly the order of things and C# will force you to have better habits by not inferring a lot of stuff.  Most of Unity's code examples are (were?) in both languages, so that's an easy way to see how they're different.

If it helps, 6 years ago I started developing in Unity using only JS because I couldn't understand C# (effectively learning to program too).  In the last 3 years, I was forced to fudge my way through some C# for a project with other "real" programmers; then I got an actual contract which basically required me to use only C# - I learned it the hard way .  And after that contract, I managed to release a game I made solely programmed in C#.  Now, I only use C# as I now understand it better than I did JS.  It might take some time, but you can transition from JS to C#.

johndman: What do you feel are the deal breakers against MD?

Thanks to all of you for your input! But for now I'm settling with Notepad++ since it's free and supports a bunch of programming languages that neither Mono Develop nor Visual Studio support by default like Python and Ruby as an example.