My first bike was a giant ocr 3 full alluminum, no carbon anywhere and I hated it. I could feel the vibrations all the way up my back. I went out and bought a 5200 and then got a new saddle and alien seat post. I put the race x lite post from the 5200 on the giant(because I gave it to a friend who wanted to get into riding) and then tooled around on it for a bit. I couldn't believe the difference it made. Thats when I decided my next bike would be a high quality aluminum frame with a few carbon goodies. my 2 pennies.

Mike