There needs to be a 21500 - that would be nice format for a dicodes tube. The 21700 is going to be a bit longer and substantially wider (and heavier presumably). I'm not sold on it to be honest - getting a bit too big for my liking..
Ya, it's a bit large. I'm gonna get one, because, must haz complete Dicodes collection, but I'm guessing it'll live over on the vaporizer or lightsaber? shelf- along with Provari Procyon and Dicodes 2380/2395 w/ extension tubes. Well, that's special! It looks cool, but do I ever actually use any of 'em? Erm, no.
Dicodes need to release something other than stabwood, such as, fer instance, titanium. Nevermind a scale, you can hold a Provari Ti and a Dicodes tube, and the former is like a feather, the latter is a like a lead weight. I have only 1 Dicodes Dani in titanium, and it's only 1 of 10 ever made and was never offered for sale; so they have experimented with it, but have not ever brought a Ti mod to market thus far. It'd be nice if they did. Talking with people at Dicodes, "it is planned" but their plans often seem to take years to attain actualization.
OTOH they have a growing collection of form factors using their chips, and other than models which are upgraded pretty continuously, they have never discontinued anything that I'm aware of; it's all still in production and can be purchased, which is cool.