played the co op and it's brutally hard. Your aim needs to be razor sharp to get head shots just to conserve ammo which is pretty scarce if i'm honest. In pick up groups people tend to rush and only get ammo for themselves.
If you're playing devastator DO pick the perk for extra ammo it helps a ton. Tactical marines leave the melta at home. It's not that useful and it's really low ammo cap is a huge handicap. Tacs that use weapon versatility, note that picking up does not affect both weapons, only the weapon you have out.
Haven't played as an assault yet, but all I can say is don't rambo and help cover your devi's backs.
I actually got to the last wave on my first try with a bunch of random dudes (one of which was horribad) and didn't die once until the last few waves (died twice then) where I was always the last guy left with no ammo and 50 orks closing on from all directions, the first time someone managed to spawn in just before I died, and the other time we lost (right at the last round

)
funny thin was I was leading the team by the end of it and I joined halfway through

In case you're wondering I used stalker bolter, storm bolter, and flash grenades
I WAS gonna play with Square and Dim, but you guys ignored me (or were playing your own round) until I started playing another game, and by the time I finished that, both of you were gone
