I have been using this bike for 7 years now and I must say I havent faced any major problem while riding it. The comfort of this bike is amazing. It was the first naked body edition by Yamaha and say what? its still ruling on No.1 in sales. The muscle on this bike makes anyone look good when he/she rides this bike.
Timely service on FZ will keep it intact. You wont face any problem if you will get it serviced every 3 months and please get it done from Yamaha service centre only and not outside.
The new edition of FZ doesnt look promising but if you areeven going for a second hand FZ16 of old model, just go for it.