I think the fire and smoke effects look great, and I don't mean to be that guy (the complaining guy), but it looks like the dark, thick smoke effects are coded to turn on at full strength (like a light switch) at the moment...
Maybe they'd look a little better if there was a transition to the full smoke effect from something like a puffy explosion or a gradual opacity increase?
I've added the original shot at the top along with two photoshopped effects to show what I mean:
...again, sorry to nit-pick and all that. Maybe though, since BoB is still in production, this might be a useful post?