I have a palmetto state armory gx-9 I believe it is with a 8” barrel and a foxtrot mike products fm-9 with a 5” barrel.

The palmetto doesn’t have last round bolt hold open the Fmp-9 does. It also has a nicer lower with a better flared mag well.

However the palmetto has been 100% reliable and I haven’t shot the fmp-9 yet.

Does anyone have experience with both and which would you choose to keep

Patience is your friend. I would not make any decisions until you've tested the fmp9 thoroughly. Wouldn't want to dump the PSA only to find out the fmp9 has issues.

THIS.

I have a frankenstein AR-9 built on a PSA AR9 receiver, and I just replaced the upper receiver w/ a blem Aero EPC upper ($100) for the LRBHO and it works perfectly fwiw