I have ridden the Mana. Not the GT just the standard variant. It was fun, very comparable to MY SV 650 in a lot of ways. If I had to commute in heavy traffic every day it would be near the top of my list of choices for sure.
What specifically would you like to know?
Lots of cool features like storage, twelve volt outlet etc. It has been over a year since I rode my friends so I am a little rusty but I remember coming away from the ride thinking...hmm that was better than I thought. The 7 speed in sport mode with the thumb shifters was fun...Minus the fact I hit the horn about 13 or 17 times.