I actually haven't shot one with the boot grip yet, but every review I've seen on them says recoil is more pronounced with the boot grip. The reason being the boot grip simply has less material to do the cushioning. Also, the stock tamer grip apparently has a little gel insert along the backstrap, while the boot grip does not.
It's kinda up to you whether you want to trade more felt recoil for a grip that conceals and carries a little better.