i'm very happy with the compact. first it looks veeeeery cool
and then it works also good. o.k. i've to change more between the 34/50. with the 39/53 i can ride the most part at 39. 34 is to small to ride with 40kph. so i've to change more to the 50. but what would you have??? do you like to have a automatic drivetrain?? it's so easy to change with the sti's. in the 80's without sti's it was perhaps discutable but no more with the sti's. 
i use a 12-23 cassette. 50x12 is also enough for each downhill. an 34x23 is for me enough also for the hardest hills.
the weight of my bike make me a little bit wondered to. the most parts are really special lightweighting. i think also the 'old' fork (it's the modell of 2003) is 'very' heavy. otherwise i don't know where i could save more weight. (...for a small price). how i said, i'll change the wheels. i'll get the lightweight-wheels soon. further i change the brakes perhaps. the zero's arent not so bad. but a little bit expensive
