I have been using this bike for around 2 years. Design and styling is absolutely superb.have seen a lot of reviews for different 125cc bikes. I feel expectations from a 125cc bike is highest when compared to other models. people expect 125cc bikes to have power close to 150cc and economy close to 100cc bikes which is not possible.
Coming back to cbf stunner, its a better bike when compared to bajaj discover 125cc(older one of 2005 which I have used for 2 yrs, the new discovers are utter rubbish, infact- a mockery of indian consumers) or glamour 125cc or shine(pathetic looks and graphics).
Bajaj as usual has reliability issues(in 3 yrs, u need to replace major spares, out of which chain sprocket assembly needs to be replaced every year) and glamour has a common piston problem and mileage issues.
cbf stunner is a good bike minus the engine vibrations at 50 kmph+ speeds.
sitting position is sporty, fuel efficiency is ok, good handling, decent quality, really good looker in the segment.
On the negative side, looking at the size, the performance is very average but honda shine has similar average issues.
Also the current option of pulsar LS-135(highly over-rated bike) will dissappear soon as per bajaj rotation policy. It is bound to have same quality issues soon.
Still not much quality products to choose in the 125cc segemnt, so go for the stunner.
Current best options in the indian bike market:
100cc - HH PASSION
125cc- Stunner/ Shine
150cc- Unicorn/yamaha fz(I still feelapache rtr 160 fi is the best bike in the country.)
180- apache rtr
220- Karizma(feel sorry for bajaj 220)