Mobil 1 synthetic ATF is also what Tremec recommends for their 6-speed TR-6060 manual transmissions, even though the OEMs use their own fluids (Chrysler use ATF+4 in the Challenger, GM uses either Dexron VI or Synchromesh fluid in the Camaro, I forget what Ford uses in the Mustang). I switched mine from ATF+4 to Mobil 1 Synthetic ATF, and it pretty much eliminated the "Tremec Nibble" going into 2nd gear when cold. Which kinda makes sense- the anti-TCC shudder friction modifiers in ATF+4 aren't ideal for synchronizers in manual transmissions.
Its funny that the back label only mentions older Ford and GM applications- its a very good Dexron III replacement and therefore works just fine in pre-electronic Chrysler Torqueflites. But never in one that spec's ATF+3 or +4... I guess that's probably why they leave Chrysler completely off the label.