First off, if your not using custom sounds, I strongly advise you do to so.
In the past I've preferred Mitsu's.
New bomb drop sounds, redone explosions, etc.
Also Tictok is just finished up a total rework of Mitsu's.
Its about 30% Mitsu's and the rest is all new material from tictok.
As to the explosion size, looks, etc. Yes, give us a customizable interface for fire & explosions. Let US decide how big, how much fire, how much smoke our system can handle.