When I say "stacks quicker", what I mean is that you'll feel the weight of the bow earlier in the draw cycle.

Think about it this way: Instead of feeling 10, 15, 30, 45, 55, 60 and then falling into the valley... you might (again, just an example...) feel 10, 35, 55, 60, 60, 60 and then fall into the valley. That's an extreme example, but the point is you hit the peak of the draw force curve earlier on. Hitting that peak earlier and holding it longer is one way engineers build speed into a bow's design.

Therefore, it's not as simple as saying a 50-lb. Allegiance is going to feel like a 54-lb. Black Ice. Fifty pounds of draw weight is fifty pounds. The only difference is when you encounter it during the draw cycle, and how long you have to pull through it.

The back walls are going to be absolutely rock solid, because of the draw-stop peg. One of the things I love about that peg is it allows me to tinker with the valley, making it "wider" or more narrow as I want... I personally prefer a nice, wide valley that gives me a bit more room for error so that if I do creep slightly, she doesn't "want to go" as much, as you alluded to. That's also a function of proper draw length, which allows you to hold the bow at full draw by squeezing your shoulder blades together properly... and having some more room left at the end to keep squeezing those back muscles together to trigger the release.

Now... would I have complete confidence in shooting a 50-lb. Black Ice at a state-record buck. Yes, I think I would, though I've never shot a bow with that low of a poundage. The reason I can say that is the same answer I give a lot of people when I'm working a trade show or helping out at a dealer event when asked about shooting 60- or 70-lb. bows: What's your goal? To stick the arrow 3" in the dirt after shooting the deer, or 6"? Bows today are so efficient, and when shooting a properly tuned outfit with razor-sharp broadheads, 50-lb. bows will cleanly slice through the vitals of anydeer with no problem -- provided you stay away from the shoulder, which you should be doing any way. And I can tell you from experience: It doesn't matter WHAT bow you're shooting in conjunction with WHAT head -- if you smack the shoulder blade on the ball of the joint directly, you WILL NOT get penetration.