I've noticed an increased amount of lag/framerate drop when using the new version of MC (Snapshot-13w01a)And I don't find the possible reason other than the snapshot. Maybe you guys already know this but I just wanted to let you know and report the 'bug'.
I'm not sure if it is the EXACT reason for it but I'm pretty sure.
Thanks for the amazing game, keep up the outstanding work. Sorry for the inconvenience.