I've shot the UL 31 for comparison purposes and didn't paticularly care for it. I thought I would but because of the light weight it just had to much vibration and handshock. I thought it was absolutely terrible compared to the other bows I have shot (not just owned).
Being from the eastern hardwwods area I don't have to carry my bows all that far, a mile being a long way, so weight doesn't enter into my bow selection. And I don't buy a bow to carry it. I buy it to shoot it. For this reason alone I opt for a little more weight that settles down and aims better, even on windy days.

My present bow, a Martin SlayR goes on the scales at just over 8lbs, but it is rock solid once I get onto my aiming point. I can shoot more relxed and accurately because I don't have to tense arm muscles to physically hold the bow still.