I've found out that I'm the slowest player on earth. Or Scout class makes me think. Or I'm hungover already.
Scout +Int(1) at level doesn't seem to be squat. Int(2) at level 2 is scarily good. Everything's a pseudo-shotty build just due to accurate "scouting". Fits really. A tactical (or even combat) shotgun just makes it stupid. Horde shells. horde good shotty mods, Boom!, hope. Profit?
Marine Badass at level (1) isn't quite so psycho, even at level 4-6. But being able to think "I reckon my Doomguy could use twice as much life right now", at any level, is seriously hard. Really, really hard. Plus you start with essentially Ironman(1) and huge power-ups. 50% berserker P/U's or invulnerablilties sounds even more than "one level" ending sometimes. Just spooge on some extra life on your next level-up. Very, very good.
Haven't Technician'd it yet properly. Instant whizzkid just seems to be a great little mod dump though. A couple of levels in to your build, just mod up whatever crap you want, be it a master-trait build or not. Much testing to be done. Instant-ish medipacks sound great too. Big armour and weapons and quick life gain. Much testing.......
I'd have to say that the scout seems the most powerful in early game (Int->Int->Fin->Jug or Fin->Jug->Int->Int is bloody amazing) but more playtime will probably change my mind a lot on that.
From mucking around with Int(2) scouts, it seems like the monster AI is, if anything, less agressive. Way more play-time needed, but watching things walk-in and walk-out of your vision, without firing a shot is somewhat strange. Big purple monsters, yayyyy, run-away-got-blasted-into-goo-due-to-AI-rather-than-bullet-magnetizing-me monsters, not so good.
More initial thoughts soonish.