I'm shopping around for a new hydration pack, preferably a Camelbak, that
I'm hoping to use for a variety of purposes. Specifically, in order of
importance:

Long day hikes
Bike commuting
Long day rides
Regular commuting (i.e. car, bus, train, etc.)
Urban trekking on vacation

Right now I'm looking at the following Camelbak cycling packs:

HAWG
Ventoux
TransAlp

I'm also looking at these Camelbak hiking packs:

Rim Runner
Peak Bagger
CrossLite 2.5

What are the major differences between cycling and hiking packs? Is it just
marketing, or are there design differences that make them better for one
activity over the other?

Any recommendations, either in terms of specific packs, or things to look
for?

Thanks,

Kovie
zen