Martin by the way in his 29 games in AA, didn't hit a bunch of HR, but still had a higher OPS than Olt did with all those HR.
Olt is a career .282 hitter with a .912 OPS in the minors. He's got power, but he's not likely to hit for average in MLB. Martin is a career .323 hitter with an .891 OPS in the minors. He won't hit a lot of HR, but can hit for average and play center field.
Granted, a lot of Martin's numbers there are from the PCL, but he was 3rd in the entire PCL in batting average and 2nd in OPS this year. The bat is legit. He's doing this straight out of Cuba, with his first exposure to pro ball coming just last year. He's a real professional hitter, as well as an actual good outfielder. Unlike Olt, he might be the Mets best overall outfielder from day one, the moment he steps on the field.
I'll take Olt if another team wants him in a 3-way. If we can flip him in a deal for Justin Upton, for example. But I have no special desire to add him to our farm system. Certainly not at the cost of our best starting pitcher.
Both Olt and Gose would have higher perfect world ceilings than Martin. But I don't like lottery tickets. Martin looks like the safer bet to me and he comes ready to win a job this spring. I'd especially rather have Martin and another prospect (the Rangers do have some depth) than just Olt.
Martin also a full year older than Olt. And while Olt k'd over 100 times he also walked 61 times in 421 PA. He has great plate discipline. In 3 seasons he posted an obp of .391.