>>58592624
Cobblemon and Pixelmon are very different experiences. If you've ever played early Pixelmon, Cobblemon's more or less aiming to recapture that kind of an experience.
I wouldn't dare say one is better over the other. There's reasons to play alpha Minecraft over release Minecraft, and what qualifies as "better" is up to the beholder.
I will say that Cobblemon feels more performant, and the models feel more cohesive, but that's kind of the end result of being a mod of a somewhat smaller scale and making blocky mobs that all fit the same art style.