I'm also a huge fan of the Bellus, seeing you have 12 Belli
@jefsview : how does it compare to the Bellus?
Fewer parts
Aside from the size and the number of parts, the Bellus delivers a warmer vape with more turbulent airflow than Serpent SMM. Because of the "stacked" airflow (2 holes), you get a lot more intake, cooling the vapor down; the chamber is also larger than the Bellus although the tank is squatter. The extra air does bring out a more saturated flavor (heavy, dense) but sacrifices heat.
The deck is easy to build on, and larger than the Bellus so you're not confined with 2.5 diameter simple round wire builds if you're so inclined. Liquid consumption still seems to be greater with the Serpent SMM when running with similar builds and airflow adjustment but it might just be that I'm still hitting it harder (just checked, and the Bellus has a 5ml tank, so that accounts for some of it).
The machining is nicer on the Serpent SMM, less parts to lose and the wicking (at least with rayon) is more forgiving; it took several months for me to nail the Bellus wicking and had flooding often at the beginning. Once I nailed it, I really loved the tank hence why I was still buying new ones into this year; tried several other RTAs, but nothing worked for me except the Bellus. The Serpent SMM is heir apparent to the throne, with a smoother airflow and punchy flavor, less parts and better machining, although you sacrifice a 1ml capacity.
I won't be rushing out to replace all of my Bellus tanks, but the Serpent SMM is a worthy replacement/upgrade if I do. All of my Bellus tanks are running fine with their original glass and O-rings and single coil adapters; not bad for a year and a half old tanks.
WOTOFO and Matt did a great job on this!