I hunt with the whisker bisquit and love it. I can leave the arrow knocked at all times when up in the tree stand and never have to worry about it falling off the rest. I've heard of it freezing up in very cold weather but it's never happened to me.
I'm willing to bet those bow shop guys critisized the WB and offered a new drop away rest to sell you all in the same sentence. Ignore what the bow shop guys say, use what you feel works best for you. The best thing about the WB is that it's extremely simple. Nothing mechanical to break or wear out. My best bow hunting is when I keep things simple and it doesn't get any simpler than the WB.