So, I watched the video of the first 3 tackles and have a few thoughts:
Kalil
Ok, I had to watch this twice because i didn't like what I saw the first time, but I was wrong. I can see he is clearly the best tackle of the 3 and the best pass blocker. Has really long arms and used them well. Not the best run blocker, but as I said before, he uses the long arms to help seal off the gap when he isn't fast enough. Some team will have a franchise player
Reiff
I really like him. He is the best run blocker of the 3 without a doubt. He explodes off the line, seals off the d-linemen and makes his way to the 2nd level frequently. He cleared out defenders with ease and could ut muscle and out technique the defenders at both levels. His pass blocking, though, is rough. He looked like he was constantly being beat and outplayed and looked like he would give up at times. Could be trouble in the NFL if he doesn't improve his pass block technique. Like Zierlein said, he might be a RT guy like Bualaga was a few years ago when he went to GB.
Martin
I like Martin alot, and maybe thats just my bias because he is a potential to fall to the Lions. Really good pass blocking. Never seemed outmatched and dealt with speed rushes, blitz, and bull rushes all well. His run blocking was very unpolished, though. While he didn't seem to look lost, he did barely enough to make some running room, and alot of that can probably be credited to the Stanford offense. Should probably focus on some strengthening in the offseason because he seemed to be overpowered at times in running plays too. There is always the possibility that Martin looked good because of the level of talent he had next to him on the line. I think he will be a great tackle in the league and be a source of comfort for some team for 10+ years.
I am no expert and am probably full of shit with all of this. I just thought I would give my tid bit because it seemed fun and I love offensive line play. I'll watch the other film from the other players, but probably keep my thoughts to myself unless I see something astounding. And also keep in mind, I only watched one game of film that was provided.