Exactly, new compatible fluid beats old fluid. AT's are bolted to the engine, they run HOT which means the fluid will go bad. I did a drain and fill with Valvoline MaxLife ATF on a ZF9 equipped 2017 Honda Pilot Elite because the CarFax didn't mention a transmission fluid change from the previous owner. The new stuff can't be worse than what's been in there for 54k miles. It's past 55k miles with no problems. I'll do another drain and fill at the next oil change just to get more new fluid in the mix. What's the worst that can happen? If I don't like it, then I'll drain and fill with the OEM brand. The drain and fill is so simple that it isn't worth keeping old fluid in there and crossing your fingers!Odds are that people who do use MV fluids in their cars also change it much, much more frequently than the average person. I think every mechanic that works on transmissions will say that fresh fluid is the most important factor (after "right" fluid, i.e. not putting CVT fluid in a non-CVT or vis-versa or ATF+4 in a trans that doesn't use that type).