Retention is fine in my JM Kydex Wing Claw 2.5 and an old Armordillo Concealment Lux, although to be fair the Lux gets all of it's retention from belt pressure. Similar to the Floodlight but without the shock cord.
I ended up getting an Insane Kydex Creations holster so I can take advantage of the slimmer profile of the PID vs the TLR-1. Cringy company name, cringy gf spamming social media as advertisement, but it's a good holster and the only option I could find for an m&p with this light.
Having the skinnier light and holster in my pants does make a difference in comfort to me. With a wedge and a claw, I don't see any difference in concealment, though.