Both feel very similar to me. The new trem has a lot of advantages like not having to cut the ball end and the integrated string lock block (so you don't lose the damn thingy!). On the other hand, there's no intonation tool for the EP (yet, I hope), so setting it up may be a pain in the ass.
I believe they're not interchangeable, because different distances between the posts and the saddles, which means if you put an EP in the place of a LoPro, probably you won't be able to intonate it, and viceversa. Please correct me if I'm wrong!