1) Garmin seems to be the only team using aero bottles. Knowing them I'd assume they tested it, though I would assume other top TT teams would have too yet they don't use aero bottles.
2) Lots of guys using bottles for that 20min TT (including Fabian). Can we assume an aero advantage? Why else would you carry the extra weight/drag in a short hilly TT, you can't really need a drink for that can you?
3) Bottle placement all over the place. Yeah some frames only have one bottle mount, but even on the frames that have two, the team members had them in different places.
Not sure how much of this relates to bottle sponsorship issues, frame mount issues, personal preferences, or all of the above. Possible that they just have "old school" mentality and shun the "technology", but I can't imagine that considering all the tunnel time etc those top teams/manufacturers put in. Other than Garmin I saw nothing to lead to any conclusions..........