I had the hip problem too with my fuel belt, and then I got one size larger. That helped a LOT. I snug it all the way down past the curve. It also helps to have on shorts or tights that do not have slippery fabric.

But I've been gravitating to the handheld on long runs. I find I typically don't consume a lot while I'm actually running - I take 1-3 gulps every 3 miles - and then drink a lot when I get home. It seems to work for me and feels more natural than running with water in my stomach - and, I never seem to get dehydrated. So I put only about 1/2 the amount in my handheld and when I get to the last 3 miles I dump everything out and then stuff it into the back of my shorts. So far this has worked for long runs up to 14 miles. I have yet to test this for longer runs.