I wish Super T would start selling tubes for the 18xxx mods so that people can swap them out to use different battery combinations. Atmomixani got it right with the Nemesis mod; give people the option to do several battery configurations with one mod. We pay enough for these things; why not give people options!?
I hate the tube gap/tube lock ring on the ELA mod [makes the mod look ugly IMO] which is why offering several tube sizes is a better option. The single tube S/P+ mods are sleek and sexy, I don't see how selling tubs for a reasonable price or including them in a $180 mod is such a hard thing. Not only would this help stock issues but it would simplify the growing number of mods on the Super T website. Why do people have to buy a completely new mod just to go from 18650 to 18350?
Again your only real competitor right now [taking into account build quality & production availability] got it right in this regard, I hope Super T considers the same business model.
A big part of the reason is that the individual precise plus tubes are finished and prepped to the remaining parts. You know how everything just seems like it's all part of the same single thing, instead of a collection of parts that can be put together? That's due to the individual attention to detail Super-T gives each Precise Plus unit that goes out the door. Take it from someone who has picked up extra tubes for a Precise plus in the past during the rare occasions they've gone up for sale. It's still a fantastic unit with spare parts put together, and is in line as far as quality is concerned to Super-T's closest competitors, but if you compare a Precise Plus with a "spare" tube to the original tube that came with it, it's not quite the same - and this is what set's the Precise Plus apart from other PV's. I'm speculating here, but I think this level of attention to detail, and pride in a "perfect" unit is why David has hesitated to offer spare tubes for the Precise Plus line.
This of course may all change now that the machining is done in house, since there has not been a run of Precise Pluses since that was outsourced.