Living Proof and Echo aren't finished and they don't sound the way they were intended to. So actually it is only Session One that we have to compare with the three Wayne collaborations.
Drop the world is probably the most overrated track that I can think of. It's just some catch phrase, a "poem" one of my students could write and an Eminem in third gear.
No Love is a beast. There's a few bad lines but overall they match each other perfectly with Weezy's laid back style and metaphors and Eminem's more agressive style and wit.
I'm not a big fan of Forever. Both have good verses but they honestly have no chemistry. It's like listening to two different songs.
Session One is quite average although they both bring decent verses. Not much to say, all the verses on the track are quite random but I think they're flow match each other well. The energy is high all the way through the track.
I think Lil Wayne is a more entertaining rapper than Royce although I feel he isn't as skilled so I don't really know who I prefer. Kindda difficult too when we don't have much tracks to compare. If they find the old chemistry again (if they've lost it) there isn't really any competetion.