So I just discovered that the Demolition Perk makes the Spray N Pray even stronger, so....thats crazy. It makes Rockert Launchers and any other weapons who have explosive characteristics even stronger. So this perk is what Im about to Max level up next.
Demolition Expert is a perk you really want to get ASAP, like early on. The power of grenades in Fallout 4 is completely different and unexpectedly more useful than Fallout 3 or New Vegas. Same for pistols, which seem to be far more useful than previously.
Also, the throwing arc you get is invaluable. You can easily clear out entire groups with Demolitions Expert lvl 2 or 3; especially when playing on Survivor mode and going up against hordes of Super Mutants. It's also far more useful against Suiciders since the splash damage radius will almost assuredly detonate their mini-nuke.
Also, important to note...
Demolition Expert perk stacks, AFAIK...
So for example, if you have Rifleman maxed, then you can get the Legendary Explosive weapons and have that stack with Demolition Expert.
i.e., Legendary Explosive Combat Shotgun's DMG would have 4x base bonus to damage while taking away 30% of targets DMG resistance. Add Bloody Mess lvl 3 and bump that up by another 15%.
You can start to get massive single hit damage here; well above 300 points per shot.
For automatic "explosive" weapons, swap out Rifleman for Commando.
Essentially, by level 45, you really could be one-hitting most enemies in the game depending upon your build and play-style.