Do you think AMSOIL 100% synthetic automatic transmission fluid is good for a Powerglide? Or is too slick because it is synthetic? Looking for opinion, good or bad

Having tried most everything, Castrol Allison Transyn has been my go to fluid for the past 5 years.
2nd choice would be Lucas semi synthetic.

I used to run Mobil 1, then ran cheap NAPA brand Type F, and now have been running Castrol Transynd for a few years.

I’ve honestly never been able to tell a difference between any of them.

People who know better than I seem to think the Transynd resists breaking down better than just about anything, so I use that.

The way I look at it is if Transynd holds up to heat and abuse in big trucks, buses, Motorhomes etc, it with take the abuse of a racing trans.
I swiched to it while running a blown TD and was burning trans on a regular bases

Allison TES-668 is my only choice and can be purchased from the following fluid manufacturers as it is a licensed product. Included is their license number to produce.
TES-668

I use the Exxon Mobil Delvac 1 ATF 668 from my local Farm+ Fleet. It’s all the exact same product if on that list.

Amsoil racing atf in mine for a lot of years now