I HAD a 2005 Roubaix triple and I loved it. When testing bikes I tried many brands and several bikes from Specialized (Allez, Roubaix, Tarmac) If price wasnt a consideration i would have gone with the Tarmac. In the beginning the upright position of the Roubaix was great but as i became more used to the bike i had them lower the handlebars for a more racy stance.
Two weeks ago while on a ride i head two "tinks". I inspected the frame when i stopped and noticed two cracks (one in the weld seam at the top tube and seat tube and one horizontal crack in the top tube near the junction). I'm 6'3" 260. with that being said. My LBS, whom i swear by, took the bike back, contacted specialized and was able to warranty out the frame for a new 2005 Tarmac Pro frameset for no extra charge. I feel lucky being able to upgrade for the total cost of replacing the front deraileur.
My points being. It seems that aluminum is only as strong as the weakest weld point. As you get used to riding and have increased flexibility you may want to go with a lower riding position. I am very happy with specialized for standing behind their product.