Paul,
Tin a bit blingish? For some that is probably true, and that is why I'm having six different coating samples done. I know that many will want the ALTiN, since I've had numerous requests for it already, while a fewer number have requested the TiN. There will be something for everyone, hopefully.
The AAA battery tube was a much requested option, so that is why it was made originally. Then a lot of folks wanted just the AAA Killer, so that is why there are now two Killers. At the moment, I have no plan to introduce a AA version.
Yes, the thickness was dictated, to some degree, by the diameter of the 357 battery, but the diameter of the driver is about the same, so one could say that dictated the diameter as well. I'm sure that a smaller diameter board could be built to suit the thinner AAA battery, but I'm not about to spend the money doing it.
Ti doesn't make for good split rings, or rather I should say that there aren't any good Ti split rings available. Even BP notes that their ring isn't that strong or resilient. SS split rings are tough, attractive and available in a wide variety of sizes. So, at the moment, the Killer's attachment point will stay as is.
Future Killers might be brighter, with a better LED, depending on sourcing both a higher mA driver and better, i.e., whiter, LED. And, of course, will continue to be offered as bare Ti, anodized Ti, or PVD coated Ti.
Thanks for the comments--hope I've addressed them all.