I use my Amigas for everything except internet and things that I have to use the PC for. Actually the only real Amiga I use regularly is my A3000/060 but it's a secondary role, my primary Amiga is WinUAE because of blinding speed and it works great.
Most of the programs I use I've written in either C or assembly. I've been finding myself writing more and more programs were I need a lot of speed and ram, especially floating point speed. Floating point speed with WinUAE is phenomenal.
Sometimes when Windows has really annoyed or frustrated me I turn on WinUAE or a real Amiga, it's very soothing.
Amigas are from an age when comuters were actually fun, MS has pretty much sucked all the fun out of computers.