RE: Why is lighter...."better"?
For us easterners, I don't see a big deal, 99% of the time we're hunting, the bow is sitting on a hook in the tree! Out west, where you hike around a lot more, it may be an issue. However it's not something you can't get use to! My bow is not light, not heavy either, but it didn't bother me when I had it out elk hunting, hiking with it for hours at a time. They don't carry all the easy though, sure you can just grab the handle and go, but that gets old quick. Next time I go I will bring a bow sling.
One thing I didn't like when I had a light bow, was that I shoot without the bow quiver on all year, then put it on for hunting. I noticed a HUGE difference in how the bow balanced and couldn't get use to it, I hunted with a hip quiver that year. Now when I put the bow quiver on, its a bit ofa difference, but nothing I can't get use to in a few shots.