I've tried using both bipods and shooting sticks and have ended up not being a fan of either. The more I hunt the more I feel that the less crap you have to carry around with you the better. I've also found that neither gave me a really good rest. No matter what height I had with me it always seemed to be too short or too high, so I was having to contort my body to get on target. I like bipods for prone shooting. But in the field I usually have a pack, and that works just as well for prone.
What I have found I like is shooting with a military style sling. I've found that this gives me as much stability as a bipod (except under ideal circumstances) while being much more flexible. I find that I can stalk and move around with the sling loop on my left arm. From there I can tuck my off hand under the sling and be ready to shoot very quickly if necessary.
Ben