Out of the box, an HFC USR-11 will tear into
the side of a pop can from a foot away with a .20g, but the BB will only severely dent the opposite side.
After the "real shock" weights have been removed from the piston, and you maybe seal a few things with a little teflon (plumbing) tape, the same shot will happily go through
a pop can fired under the same conditions.
Compare this to the guns you and your friends already use. Consider if the price of an HFC USR-11 (and possibly the price of a small roll of teflon tape) suit what you want your gun to do. If it all seems overboard to you, then just go for the UTG - it's dirt cheap, and if you want to "upgrade it"
down the road, you still can (if only a relatively small amount, in comparison to, for example, some $600 gas sniper rifle).