For me, the default ArmA building collapse effects are rather weedy. (I generally think all ArmA smoke is weedy ) so here is the first part of my solution:
DM Smoke Effects building collapse.
It's a config, so make an @DM folder & pop it in there, do the shortcut thing. Basically the config makes the building collapse effects ten times bigger, and last ten times longer. The difference is quite stunning, and that's without touching any of the particles. It (or an improved version of it) will eventually become part of the general DMSmokeEffects addon.