Hahah I like your little sophistic games. The one who dreams will never be a vegetable, the one who doesn't already is. The lack of imagination means death especially on any kind of battlefields.
I already know this one, quite an intersting mission, good suspense - especially the part with ork nobz trap inside the building. In this mod orks and especially ork nobz or mega armoured nobz are reall melee beasts, they run very fast, have a high immunity and one power claw attack is enough to take down a marine. In one mission in an urban area i saw several nobz taking down whole marines squad in melee, the marines were taken by surprise and didn't even manage to react. But today i've played one of the best missions in this mod ever -Alpha Harbour -very professionally made. You played as black templars SM, the group consisted of maximum 4 players. The task was to make an ambush for a chaos convoy, then head deep into their harbour base to destroy fuel tank and finally deeper into the area to kill an Alpha Legion Chaos Lord with his retinue and a defiler. There were many surprises on the way, it was a very difficult mission as i played with only one of my friends, we finished it after about 4 hours thanks to the possibility of revivals - this really felt like a proper Wh40k combat mission .
Pff,who said Space Marines must ride sanctioned stuff? View: http://www.youtube.com/watch?v=_kXiFSHE56U
Space Marine is an action-game. Operation Flashpoint is a strategy one. Comparing them is a tad silly.