well just like PO2 titan and kappa mode the mobs on PO3 current release are op!! and there is a current bug with the release with hostle mobs that can crash a server due to the high ping it generates!! but the newest beta supposed to fix this error!! hope this helps in your decision!
Rough Mobs mod was removed in latest beta, mobs should be a lot less "OP". We have a plugin that removes entities if there too many of them just like any other servers. As for the high usage entity if it was fixed then all good