Meh, the last prototype I purchased was the LingYun II and then the retail version came out a week later. Same cube, even the caps have logos which were absent on earlier prototype cubes from "DaYum". I can't even prove that my LingYun prototype is really a preproduction model because of the fact that it has said logos.
50$ for a prototype GuHong II. Nah, I'm sitting this one out. Don't like the GuHong that much anyway. And as Kirjava said; torps suck. Mainly because they hold a good cube back.
There's nothing better than a first gen LingYun anyway. I actually stopped using my stickerless LingYun as my main practice cube just to keep it special. When I take it for a spin now and again, it makes me realize just how much better it is than any other 3x3x3. My black LingYun is awesome too but I made the mistake of putting tiles on it which ruins the grip, so I don't use it much at all anymore.
What's left to buy nowadays as a collector?...C-IV? Merely a rehash of the old-style mech that implements some DaYan/ V-Cube stuff...Sure I'll buy one for the collection, but I already know that it will dissapoint. I prefer getting 3x3x3s that feel different and aren't that good as opposed to getting a cube that is a bad sequel. At least "lesser" cubes invoke lower expectations than some of the "go safe" persiflages that are being thrown out as of late.
If you own as many 3x3x3s as I do, then only the particulary good ones and the pretty bad ones stand out. The "noise" in between just reverbs into mediocrity and fails to at least entertain.
And now some German rock music, just to make this post(and the GuHong II) even more redundant than it already is: