Well I managed to wreck my allez elite in three and a half years. Part of that was keeping it in a shed I reckon, the rest was the amount of wear it had. There was some cracking of the carbon at the top of the fork and I think it was caused by the steerer corroding - which made me question its safety. The headset bearings were also quite rough. What put the tin lid on it though was that I broke one of the cable guides when trying to change the cables. The metal cap had bonded to the guide and the aluminium in the guide had deteriorated so it fell apart when I tried to remove the cable.
Having said that it owed me absolutely nothing. It was an £850 bike that I got a few months old in 2010 pretty much unused for £540 on
ebay. I got £130 for it in the condition it was in. So over 12,000 miles and a life-changing amount of exercise, hard work and fun later it must rank as the best purchase I ever made.
I've just bought a tarmac on the basis that the allez really worked so it is worth sticking with the same brand / size. The cheapest new tarmac is the sport at £1500. Last year's sport might be available for around £1200 to £1300 but it will have the older 10 speed 105 rather than the new one.