Am looking for opinions and advice on the following:

I have a chance to buy either a 2009 Madone 5.2 with full Ultegra SL or a 2008 5.5 with full Dura Ace (except Bontrager Race XL Crank). The 5.5 is $200 more than the 5.2 but is virtually in new condition, while the 5.2 is in very good condition but shows some signs of wear. The only key difference between the 2008 and 2009 Trek Madone lineups as far as I can tell from my research is the replaceable derailleur hanger on the 2009. I’m trying to get a sense of whether the replaceable dropout is enough of a design improvement to go with the 5.2, or whether to go with the better setup on the 5.5 (and newer condition) without the replaceable DH. Colour schemes don't matter - I like them both.

How common is it to bend a DH?
Thanks