I personally think there's a huge variance in different pure batches of normal ketamine. And as I understand it, it's now accepted as fact that this stems from the difference in effect from the 2 isormers of ketamine.
Not really. Regular ketamine synthesis won't yield different ratios of isomers, synthesis that do are very impractical und unlikely to be done in any non-exotic scenario. Usually the synthesis yields a racemic product which means 50-50 ratio (this goes for all substances that have only two isomers like ketamine!), not 70-30 or 15-85 etc, just 50-50. The s isomer will be split up by pharmaceutical companies (a relatively simple process) and the r-isomer will be converted into racemic ketamine again in a separate process. Different companies use different procedures, but this is how it goes down if I'm still up to speed. Isolated r isomer will usually not end up on the street level, since there isn't any medication that contains it in isolated form.
That being said, different batches on the street COULD be resulting from a dealer mixing his racemic with s-isomer in different ratios, but imho that is highly unlikely to be a regular thing and I've never seen any criminological reports suggesting it either. Therefore I conclude that the different ketamine batches you see on the streets these days are either cut with a totally different substance (enough out there, take your pick... MXE (ugh) and tiletamine (YUK!) have been found in street samples) or you are seeing s-isomer vs. racemic ketamine. Also the concentration (assuming it's cut with some inactive substance) can considerably effect the quality of the experience and so can set and setting.
Different ratios of the isomers in street product are still very unlikely, though surely not impossible. Considering how highly sought after ketamine is, this would require a dealer to source both s isomer and racemic ketamine at the same time and not prefer the kicks of being able to offer two different batches over mixing them together. But then if he does mix them, you should see dealers with 4 or 5 different batches (e.g. 60% s, 70% s, 80% s...). Never heard or seen such thing.
Personally, I'd just like to see some plain old phencyclidine again. It's definitely the most kickass dissociative I've ever done (and many times so). I'm at a total loss why it isn't making it's rounds on the street with it's relatively easy synthesis and dissociatives being pretty big nowadays.
Plus, I miss funny news reports of naked people fighting off 5 police officers with a traffic sign that's been hastily ripped out of the concrete by purely primal rage(+pcp) fueled superhuman strength.
Plus2, it would stop all these godamn leeches of rc vendors making money of the low availability of real drugs to internet kiddies. Fucking nasty-ass mxe never deserved 1% of the fame it received.