I agree with a lot of what AKAChip said. Honestly I mostly watched the QBs and the receivers.
QBs - Willy looked pretty good. Good zip on the ball. Quick decisions. Nothing overly flashy but I thought he was throwing the ball accurately.
Hall was his usual self, decides where he's going to throw it, and it may be into a swarm but he does get it there.
Marve may have the tools but he was showing a lot of "deer in headlights" not knowing where to go with the ball at times.
Would say that Brohm had him beat out in that respect, but a lot of the time Brohm was just making the easy throw (which isn't necessarily a bad thing). I think Brohm also comes off as the stiff, sit in the pocket NFL QB, but I may be wrong.
WR - Mario Urrutia was getting a lot of throws and looked fairly shifty and speedy with the ball in his hands (especially for a big guy). Agreed that he had some of the better hands today.
I would say C.J. Tarver had pretty good hands as well. He is a very interesting player. At times it didn't even look like he was trying to outrun people, but was still outrunning them.
Kemp, well, let's just say Mike that you didn't stay long enough to see some of his good work. I know what you mean though, early on he was flat out dropping balls and didn't look super great. But in 1 on 1s he looked dominant against some of the DBs out there. Ran crisp, fast routes and made some of the DBs look silly. But also dropped one in Skelly late.
Taylor Renaud looks to be one of the depth guys that could stick around. He had more than one good catch out there today. But again, the level of competition he was facing wasn't exactly stellar.
I don't know if I have any more to share, but I'll let you know if I think of something.