I've had both isomers, first it was S then a while after that the R was stocked. I found the S-variety to be way more anaesthetic, mentally it's a softer experience like you increasingly forget who or where you are. Walking is often not an option, but on the body it can feel like you were hit by a freight train.
The R variety is much lighter on the body, loss of coordination certainly, but it doesn't really put you down fast at all. It leaves you more present but at the same time jumbles up all sensory information making it more disturbing - not soft and cozy at all but hard, edgy, quite manic actually.
Took me a while to get the feeling for them, what they were about but right now it's clear as day. If I take the racemic I can distinguish the parts of the effects that can be attributed to the isomers. My source was an excellent one, the purity of both was also the best I ever saw.
Merging into the K isomer subthread.
Also, if you disagree that S-(+)-ketamine is more anaesthetic and gentle take a look at the complete first page of this thread. TheTripDoctor comes to the same conclusions as I did...
I find the question which isomer is more psychedelic a really hard one and I could understand people answering for either one. To me the R-(-) is more delusionally and fucked up psychedelic while the S-(+) has more of a wholly rounded emergent state coming from it.
The racemic is still a great mix so anyone who doesn't have the isomers available: you're not missing that much apart from a satisfied curiosity. Though I may change my preference from racemic to S-ket. Ahhh the good old days.