Was in the same boat as you, though not entirely displeased with the Blu(when using cartmods) as you are, but still wanted something better.im going to keep searching so far idk why but im stuck on the vapor king but my mind is still open still nothing back from blu looks like im going to have to keep it and let it gather dust i need more input
Ending up going for a Riva(another Ego clone) after seeing them being suggested all over on here, and could not be happier!
This thing just blows the Blu out of the water. I had to charge the Blu batteries 6-7 times a day, while the Riva batts are lasting a whole day of heavy vaping. The 510 attys alone are good jump and give better vapor production, and the carts easily hold twice as must as the Blu(I'm using Kristin's Reservoir-Straw mod).
Add to that, I actually got my Riva kit for less than the Blu kit!
Go for a Ego\Riva\Tornado, you will not be disappointed!