Practicing is more than figuring out where your pins should go. You should first practice with your form until you can get good groups at a distance (out to at least 60 yards). Then practice from twisted, awkward postions that you might experience in your tree stand. Then practice from your tree stand. Once you have done all of this and can maintain 6 inch groups at 40 yards from any position in your stand, then and only then are you ready for the woods IMO.

No amount of technology will replace that.

Besides, there is always buck fever. Could you imagine the ribbing you'd get if you did miss with this device?[:-]