My bike is a Prost Sport Edition, which means front & back discs, shiny steel foot-plates, and it's liquid cooled. Also included was stupid bright red mirrors!
This bike is great, the acceleration is unparralleled by my friend's bikes (standard Speedfight 2 50, Katanya 50 & Vivacity Sport 50), and I have made no modifications to it.
Handles lovely, very predictable at the limit, also has much heavier/more feedback steering than the standard Speedfight 2 & Katana.
Braking is also very good with front & back disc brakes.
It sounds a lot better than the others too, they sound like supercharged Dysons, but mine's quite beefy at idle.
Is derestricted and can do about 55mph on a flat, tucked in with the wind behind (have got 65 down hill though!)
I have only had the bike about half a year and quite a few things have gone wrong, but I believe this is only because I go everywhere at 55ish and it gets used to take me fishing, about a mile drive off road (actually does it with ease).
Fuel consumption is very poor, I get about 25 to 30km per full tank!
Only problem I found with the dealer is expense e.g £23 per front light, also wanted me to pay £100 for a USED exhaust, and finally I was quoted £450 for a new full plastic set!
My dad had the bike for 3 years before me to take him to work and back, (about 1.5km there and back - hence the low mileage when I got it!)