Hi! I had the same doubt recently. So what I did was starting with OOO by itself to try it out. In my experience: it didn't make me OP, but it turned me into a little girl lost in the woods during satanic chants. You DO get better loot (if you can open the containers), and I found it pretty balanced to be honest. After a while, I was able to finish some starter dungeons (Vilverin, Sideways cave, Fatback cave, some forts) but my melee-only character was not being rewarding enough. So I read on some forums that OOO makes Mages kick some sweet ass, and decided to try it. After that, I installed MOO and began using both (MOO + OOO) together, and It's been great so far! I also use the Realistic Leveling mod just to change things a little. And also Balanced Magic. MOO doesn't conflict with OOO. OOO makes the game harder, not only leveled to your character, and more, much more diverse. Also many factions and such like better bandits, amazons, more monster groups and others. It's cool because you won't own everything at lvl 1 anymore, and forget the "min is max" rule, you NEED your atribute points. If you use Realistic Leveling, then nevermind, but if you don't, I suggest you use the "always +5" mod, that always gives you +5 points in atributes you've leveled up through your skills. I also suggest using the Scout mod, so you can see the enemie's levels, HP, Mana and Fatigue bars. It's much easier to know if you can possibly handle a situation if you can see these numbers. But I suppose it can be fairly un-immersive aswell. Either way, both mods work great together! At least in my personal opinion. Let us know what you've chosen!!