Saw the first three games against Midland.
Singleton - moves well for guy his size. After the first two games, I assumed he could hold down left, but after seeing him there in the third game, I highly doubt it. Poor breaks and doesn't seem to be athletic enough to finish the plays. His approach at bat is great, like a good pro. He recognizes pitches well, waits for his pitch, dials his swing down with two strikes, and shows aggressiveness when it is warranted. Hits to all fields, and has pretty good power already. Need to see him against better pitchers, but he was very impressive.
Wates - he makes contact at an Altuve-like frequency. Also has a good approach. I'm not knowledgable enough to know if it is bat speed, strength or something else, but the ball doesn't jump off his bat as much as his contact would warrant. I only saw him play left and didn't see a lot hit at him, but he didn't look great out there. Arm seemed marginal. He has speed, but is not a blazer. Overall, he was very impressive. His ceiling seems higher than a fourth outfielder.
Villar - I keep reading that he is a prospect, but not sure why. He's no better than when I saw him last year. Sloppy and undisciplined in the field and can't hit.
Barnes - really enjoyed watching him play center. He breaks on the ball exceptionally well. There were a number of balls that looked like major trouble off the bat that he made the catch look easy. That being said, he seems incapable of handling off speed pitches. It got to the point where everyone must have known a curve was coming. I'm sure Barnes did too, but he can't recognize or lay off them.
There are some other good minor league position players, but I'd be surprised if any make a major league roster.