D&D 5E Grindy D&D Next Combat

[Echohawk]

Is there a new set of rules available more recent than the April playtest packet?

No. Latest playtest packet release was 2013-04-11, and that was the same as the packet from 2013-04-01 just with the addition of the Bestiaries for S1-S4.

(There's a complete history of the contents of all of the playtest packets on the ENWorld wiki.)