Aero bike considerations for purchase I am trying to decide between aero bikes from two different brands.  What are some of the things I should think about when comparing these two (or any other) aero bikes?
There are several things (such as fit) to consider when buying any bike.  However aero bikes have some special considerations to be made.

Comfort 

Has the design compromised the comfort by making the ride overly harsh.

Weight

Are you going to be doing a lot of climbing on the bike?  Aero bikes are heavier than normal bikes due to the tube shapes, however some aero bikes are particularly heavy.

Maintenance

Are you going to be looking after the bike yourself?  If so, maybe you don't want the nifty hidden brake calipers integrated into the fork.

Travel

Are you going to be travelling with the bike?  Is any integrated bar/stem and magical cable routing going to cause problems?

Wheels

Do you already have your own deep section wheels?  If not, does the bike have a good set?  Wheels will give bigger aero gains than the frame itself

Tyre Clearance

Given the increasing popularity of larger tyres and wider rims, does the frame have clearance for larger (28c) tyres? 

Aero Bars

Are you potentially going to want to use the bike for  triathlon or time trials?  If so can the shape of the handle bars accommodate clip on aero bars, or does the manufacturer produce their own special version?