persnally i hate the PM-9, it has more kick, is weaker, has a smaller magazine than PP90M1, and only 90rpm faster, which as 1000rpm doesn't make a difference.
I run with PP90M1 rapid fire/extended mags (attachments)
Quickdraw Pro / Assassin Pro
Steady Aim Pro / Sitrep Pro / Sometimes Stalker Pro
i recommend having steady aim on if using assassin pro, as it helps a lot in situations such as campers, and sit rep seems less helpful now, as (for me atleast) the game volume (such as helicopters, gunfire and explosives) has got much louder, without sitrep being more sensitive.
its according to what gametype u play.....kill confirmed i like the pm-9 it blisters up close and i use ext mag and range W steady aim and mostly hip fire and use a mp9 with red dot or holo for those long range battles (better then pm9 lol)
stuns and semtex support if you rush nonstop
i play SnD like there's no tmrw and just brutally murder people with the PM9 even without range i can hit across the map (just shoot in burst and don't hold the trigger down) until they get close then unleash and u should get hit markers like crazy from far away but they usually stop and turn around towards u so just shoot to get their attention as a red dot will show up on their map....wait and then spary down however i use the sights on it i think they are good as hell when i use mines
I use the PM-9 but mainly playing hardcore dom.
PM9 w/ thermal and kick
P99 ext, mags
ext. conditioning pro
steady aim pro
frag and trophy (for capping b flag)
soh (reloads are soo sloow)
I pretty much hipfire unless there is smoke on the flags thus the thermal and can get up close quickly with extreme conditioning and burst fire is a must.