I just got a Fastrak SD 54 and I love it. I can't give you a comparison as I have nothing to compare it to except a couple of riding tractor mowers. Never been in the mud or overly wet ground -- always mow when grass is dry.
It looks like a golf course when done. Real flat and smooth. Stock blades. I have one road cut that is steep and I back up then go down the opposite direction. Lots of power. The deck seems to load up with glued on grass, but I have NEVER cleaned out any deck before, so don't know if it is a lot of loading. Doesn't matter, as I jack it up after every use and wash it out.
I also considered the Raptor SD, but since I could afford it, and not getting any younger, I paid the difference and am happy.