a BTA system can easily cost $100+. A bag of 50 zipties cost me $4.99

I've tried a few different bta systems but the simple zip tie cage a regular bottle just works best for me. Splash issues, leaking problems, awkward refilling baffles... it's just easier to have a regular bottle cage for me to take a hand up and slap it in the cage instead of dealing with the other issues. I got sick of trying out different systems just to be let down with minor issues. In the end it came down to why spend the extra $$.

I understood that the BTA systems you mention are drag- neutral whereas a normal bottle BTA reduces drag.
And indeed bottles on the frame mostly increase drag but what do you do if you need them?
Some people do not like grabbing behind the saddle so they prefer a bottle on the frame instead of one behind the saddle although the latter could be more aerodynamic.

Anyway, I never saw two bikes with the same bottle- politics. It is very individual.

Read this and decide what works for you:

http://mx.cervelo.com/...nd-aerodynamics.html

Great article thanks for adding that in there. I thought it was great that Cèrvelo tested the other bikes and where the best position for the bottles would be. Great info.

Still wondering from others why the traditional bottle over say an x-lab torpedo or profile design bullet?

Other than the aforementioned issue of price, there's the issue of refills during a long race.

Using a standard bottle + cage combo means you can just grab a new bottle at the feed station, dump the old one and you're good for another 20 miles or whatever. Refilling a dedicated BTA setup is a faff and the time you spend out of position doing it will probably cost as much time as the setup saves you. The major downside is obviously having to remove the bottle and drink normally rather than with a straw.

On balance, my opinion is the bottle + cage seems like an easier setup to deal with when racing so I don't feel much of an incentive to drop $100+ on a new setup.

Edited to add: I'm talking about a standard bottle + cage mounted between-the-arms here, not on the frame; I'm not a complete heathen.