that actually looks to be a pain in the azz, to me, takes 3 batts, which means one would need 6 18650's to run this box effectively, two married sets of three. 
Do own the Sigelei 100, Cloupor T8 & T6, and all three find quite vapeable.  Build quality, fit and finish goes to Sigelei, like that they have both screws and mags for the back cover.  All around general vape, I do like the T6 best.  Feels great in hand, and uses a single 26650 batt, so it's a quick swap out.