In this instance: Desktop, graphics. This from a hobby point of view, though! Which means I have very little time to achieve anything and occasionally don't touch the code in weeks. I've come to write code that is a) trifty b) readable c) works on compile d) leverages type system for composable code that has a specific "correct" way to do things.
So I can return to my code, which I've completely forgotten how it works, see that it compiles, read it through, and continue working. Noticeably: I do not need to care about the tooling because it just works. I don't get a shiteload of weird exceptions when I run my code (looking at you, Clojure - yes, I'm a noob) and since the Pythonic and mutable nature of F# allows me to write code in the way I enjoy the most it feels like a glove. There are a few oddities occasionally and some bits are a bit more verbose than in other languages (Clojures collections spoil any other language) but the overall experience is that I can focus only on my code. For me, it's a pain free computational substrate, and free as in beer now that Visual Studio community edition is out.
My progress is really slow but always worthwhile.
If you are interested I found Jon Harrops "Visual F# 2010 for Technical Computing" really good practical introduction, Don Syme et. alls "Expert F#" a good reference book on writing general stuff in the .Net ecosystem with F#, Petricek's "Real-World Functional Programming" a very good introduction to various application patterns and Sestoft's "Programming Language Concepts" a great book and online reference on writing interpreters and compilers (http://www.itu.dk/people/sestoft/plc/).
*At work I use C++ on MS stack.