I'm thinking of buying The Trap Door fall-away rest. Any thoughts?

I have Mach 4, it works great for both hunting & indoors.
I like for the fact that it very simple, no cables or stings, just set it and shot it.

BearCountryArchery

It seems like a good rest. However, I'm kind of leery in the fact that they seem to change the design every year. I mean how can you improve on a rest if it falls reliably and locks tightly?