I haven't had the pleasure unfortunately but I've wanted to try this one for years and would be ecstatic to find an affordable source for the pharma version (some RC sites have occasionally had it as HCL in raw crystal/powder form I think but eh, with such a narrow therapeutic window and steep dosing curve that seems like a dubious pain in the neck, and I vastly prefer pharma everything anyway).
I've heard about the strong histamine reaction--that's universal it seems--but I still suspect I'd love it. It binds to the b@rb!tur@t3 site of the G@B@-A receptor (as does, interestingly, z0p!cl0n3, which I love and have a script for as an indispensable sleep med), and I just seem to respond better to those sorts of G@BAergics than I do b3nz0s and the like. (I like b3nz0s occasionally too, don't get me wrong, but they're super inconsistent for me and I get, bizarrely, strong anxiogenic/heart-racing paradoxical effects if the dose is too high. I'll never forget the time I took 60 mg t3m@z3p@m and nearly had a panic attack, that was weird...) I was born in the wrong time/era of meds I guess, lol!
I also just tend to adore and respond well to "weird"/obscure/miscellaneous d0wners in general, for some reason, compounds like c@r!s0pr0d0l/Sewm@h, (es)z0p!cl0n3, et!f0x!n3, recently z@l3pl0n, etc are my favorite meds EVER at least from the depressant side. I even loved @fl0qu@l0ne back when I could get it (tragically seems unavailable now), even though that's barely psychoactive, but it certainly has its uses. Anyway yeah I'm rambling but cl0m3thiaz0le sounds absolutely awesome (though I'm sorry you had such a bad experience with it). If anyone ever comes across a legit source for the torpedoes, please let me know!