I wasted a bit of time and effort trying to find that perfect sweet spot and came to the conclusion that I am most happy with a normal ego battery and a T3.
I was a heavy, heavy smoker and picking up cigarettes was so thoughtless and effortless and became such a part of my daily routine that I developed habits to accommodate it automatically. Vaping needs to sort of be the same for me or it wont work. Therefore, it is imperative for me to always have a charged battery and a full Clearo lying around so vaping is as effortless as smoking was for me. I can't "think" about it. I just want to pop it on and puff.
Having said that, I do have some twists and do enjoy the versatility of being able to crank the heat up a bit if I want to. I almost always end up around 3.6-3.8 even when I use the twists.