I use the x4 but I have to run them at 48-55w depending on the juice I'm using. Its good flavor, not outstanding tho. It does get quite hot after 4-5 drags, but if you don't mind that, then you should be good. If you chain vape, go lower watt but I wouldn't recommended beneath 38. Then you might have to take couple drags before you actual get a flavor that might be satisfying for you. Might need to go down in nic, I personally can't vape above 4.5 with the 0.15 without having a very harsh throat hit. Different on the Q2 o.4/0.6 ones.
I'll keep the heat in mind. I have a Cleito on a Sigelei Spark 80w, single batt. I'm having continuous, extreme heat to the tank. Battery can't take it. Will switch to dual batt. I'll need to do the same with both BB as well. VW at 50-55w is normally my sweet spot. And yes, I think it's time to drop to 12mg. As it stands now, being at my desk with 3 rigs, I'm not vaping as much. Good time to drop. Yay me!