I was in the same boat, decided on the Rugged Obsidian- paid just a tic in length penalty but, for me at least, the flexibilty seems worth it.

I have a Mystic X on my MPX with Liberty's 3 lug adapter. I have been very pleased with the set up, the QD is awesome to pull the suppressor of for packing/etc. The Mystic is a long can but it suppresses the MPX well. I only have a couple hundred rounds down it but have had no issues with gas, etc. ...

Thanks for the info! Been lurking for a long time, have learned and continue to learn a lot! Safe to say that all my stamps have been purchased after much research here! I pick up my MPX-PSB tomorrow, I'll answer my own question so the group knows. Now to decide on how long to get ADCO to chop my ba...

I've got a MPX pistol coming with a brace. Does anyone know if the brace buffer can be unscrewed and replaced with a milspec buffer when my F1 goes through? (Goal is to have it submitted within 2 hrs of pickup!). Plan on chopping the barrel and running with a mystic x on a trilug. Thx!