I tried the mobGriefing false for a while. So here's my experience:
It sounds like a good idea in principle, to protect all those expensive machines, but creepers just become a non-issue altogether. There is no fear anymore. With even just plain unenchanted iron armor (on Normal difficulty), you can just take the hit and carry on. Creepers become less dangerous than skeletons and zombies because the creepers only attack once and then you don't even have to kill them.
Also ghasts no longer break netherrack, making the nether far too safe to wander around in.
Those are just my opinions though, and different people want different things from the game, so it's entirely your choice.
If you're looking for balance, I wouldn't disable mobGriefing. A more reasonable solution I've seen is people asking for mods/settings which increase the explosion drops to 100%, so you can at least repair the damage, but I haven't tried any such mods.
If you're looking for easy mode (and there's nothing wrong with that, different people play differently), mobGriefing false is exactly what you need.
