I love my acrylic version of the mod, and am toying with the idea of seeing how arctic fox works on them. Temp control in SS mode on the regular firmware has been working very nicely.
the Hcigar Towis T80 is a bit on the big size, but it will take up to 25mm atties, it performs well and is comfortable in the hand. I like mine and it is available here
I will probably sound like a HCigar fanboy but a bit bigger sized the dual battery Werewolf also worth considering. I liked mine so much I bought a second, I use them for more DTL tanks (Intake & OBS Engine 2 RTAs), but worth considering.
That said you would need to do some serious vaping on your Beserker to be worried about needing a second battery for battery life (you could always just carry a spare if it was an issue).