I think the design of the glas straw that sits in a silicone "extender" sleeve is a better decision than glas in glas straws. (think glas grinding against glas, still the need for silicone to make the two glas straws airtight, more difficult to take apart/re-assemble, higher chance of braking the straw/s)
All we have had is speculation as to two possible arrangements. We don't know if either is true, or if there is another option we haven't thought of.
(And it could very well be: Silicon sheath (breakage), glass outer shell, silicone gasket (coupling), and glass straw. This would keep it GonG when fully extended, but we have to wait to hear if there is that outer glass shell in there. Hopefully the video tomorrow will tell us more.)
I have mentioned that there *will* be coupling in here somehow (there are at least 2-4 joins), which is most likely silicon. (As you point out "glas grining glas...airtight" etc etc) So there will most likely be some silicon in the path, but such a minor amount as to be negligible over the whole course.
EDIT: I drew a quick sketch of what the dual-glass tubes might look like. I count 3 points where the 4 pieces of glass(or glass+ceramic) will have to be gasketed, all very minimal in the over all picture.
I could be *totally* wrong about this, but, hell, I gotta have something to do while waiting for them to take my money.
/EDIT
I do however hope that the guys at the company won't let them get ahead of themselves...
From everything I've been reading about their previous product and this one, I don't think that will be a concern.
be nice to be able to just quickly replace the silicone sleeve, whipe the glass straw and start vaping again in a couple minutes. (for that reason maybe also the choice of buying/adding an extra glass screen)
That's all user accessible for cleaning and I believe it's been said "replaceable" So there should be parts.
I don't know how removable the glass screen will be, but it was mentioned a non-glass screen can be added for those that want it.