This thread is getting a bit derailed. To continue the derailment, I have to say there are many options available between bottle-cage-on-frame, and full hydration pack. It's not simply one or the other. I am firmly in the camp of dismissing an entire bike based on having or not having two bolt holes on the frame is silly.
:fruit:
[EDIT]: this post was obviously written before all the excellent product suggestions at the end of the last page…
Ride, don't slide.