I've purchased both games over the last 3 or 4 years and for my tastes, MLB2K was a better game.
The only thing holding it back was poor animations and player models.
If it looked as good as it's competition, I think it would have dominated sales and we'd be talking about it in the same breath as NBA2K.
I still play 2K13 regularly and I'm amazed with how great the presentation and commentary are.
It's like listening and watching a real telecast.
Unfortunately, I fear we've seen the last of 2K baseball. Kush did too much damage to the brand. By the time VC took over and fixed that mess, it was too late.