I own a HK USP Expert 9mm and it handles hot loads very well, much thanks to the recoildamping system. The slide doesn't hit a solid stop as the guiderod has a stiffer spring at the end.
Whether you should buy an Elite or an Expert is completely subjective. I'm sure both will handle .45super without problem. How the recoil is felt is another matter as the USP's are quite 'tall' guns with the barrel high above the hand.
Personally I don't like the look of the Elite with the extended slide and barrel but of course it also comes down to what you intend to use the gun for.

// Karl, sweden