I have had the Trek 5500 for around 4 years. I bought the frameset so that I could build it up with a Campagnolo Groupset.
The red paint job was chosen because the US Postal team ones changed every year and tended to date the bikes. Of course, when they released the first Madone with the new shape, my 5500 dated overnight. Oh well.
I have recently upgraded to the 2007 Ultratorque groupset. As well as being really easy to build and really quiet when running, the shifting is sharp and precise. I haven’t done enough km’s yet to say too much about long term perfomance.
The Time pedals have served my knees well but thet are getting a bit old and they may be the next thing on the upgrade list (the pedals, not my knees).
The Ksyrium wheels are strong, responsive and light enough for all the climbing I ever did while racing. I do find the Bontrager RaceLite tyres a bit too sluggish when compared to the Michelin Pro Race tyres that I had previously.
Despite never having changed the bar height from the first day that I rode the bike, I still haven’t gotten around to cutting the excess steerer off. You never know when you may have to completely change your riding position and lift the bars up 3cm.
After steel and aluminium Bianchi’s in the past, I love the ride of the Trek carbon fibre frame. It is light and responsive and really lets you get the power down. Maybe one day I will get to test it up in the Dolomites, here in Italy.