Lead Machamp stopped being good. It has a MASSIVE spike in usage in April, but just as quickly as it went up it started sucking because a bunch of common leads (Azelf, Metagross, etc.) have started carrying psychic-type moves. Also Togekiss usage seems to have gone up.
But seriously, every Azelf or Metagross I've seen today has had Psychic or Zen Headbutt. So yeah. Don't use lead Machamp for awhile because it'll die immediately.