The only reason a host of states is NOT keen on implementing GST is because they would be forced to tax certain sectors at flat rate instead of the totally random and ad-hoc rate at which they do now!

Show me a very good reason why would someone pay road tax @7.5% for ex-showroom price in Haryana and a totally atrocious and unacceptable 14.5% in Karnataka! Roads in Karnataka arent made of Mysore Pak or anything...and in any case Haryana roads are better.

Opponents are crying hoarse at the complexity of the whole rollout, but for me its more of a convenience since the whole rigmarole of border check-posts will be done away with, reducing haftas and the entire inspector raaj will be finally disbanded. 
The final bit will of course reduce the extra income of the political classes and their pet goons and friendly baniyas, but most people will be happy otherwise.