I got mine at the Racing Superstore in Arlington. They took a day to get it from someone else though.
All that aside, I was running Valvoline synthetic tranny oil before I put the MTL in and I think I liked the Valvoline better. If anything there isn't a noticable difference. Most of the guys here like the Valvoline stuff better, plus you can get it at autozone or Oreilly's.