Brought my bicycle to the shop today to upgrade the parts. Actually I was more going from a flat bar cyclocross to a road bike handle bar, and as a consequence, got to change the brake levers (STI) gear shift, rear derailleur into one that will fit a road bike. Was thinking of a Shimano 105 group, but finally why not just go to Ultegra all the way. AT the end, the cranks were changed as well.
Took some time to get used to the road position, and then I realised that the original setting was a little wrong, the seat was too low, and too far back etc.
Overall, I'm quite happy with the Shimano Ultegra set, shifts well and you dont feel any lag between paddling and the power getting to the wheels. Unlike my previous SRAM X9+Truvativ combination that's more suited to mountain bikes.