I'm an (open-minded) racer and designed my last frame around using a CamelBak (and I bought the smaller CamelBak as well as the jersey with the integrated bladder pocket in preparation for the frame). I ended up using bottles instead, for races and for general rides.

CamelBak advantages:
- insulated
- lots of capacity
- "out of the way" on the bike
CB disadvantages:
- first bit is not insulated (the fluid in the tube)
- can't tell what's left
- "in the way" of pockets

I now use insulated bottles instead.
Advantages:
- insulated
- can tell what's left
- first sip is ice cold
- not in the way of pockets
- the Podium Ice bottles works well enough that after 1+ hours in 90+ degree heat I still have ice in the bottle.
- refilling is easier, especially compared to the jersey version of the CB.
Disadvantages:
- bottle is bigger than regular
- bottle is less flexible than regular
- takes up room on frame
- doesn't have the same shoulder as other bottles so doesn't hold quite as tight (but with the Specialized RibCage I've never dropped one, even on rough courses that cause moved bars, moved levers, flats, and damaged rims).