I remember reading (i think in the DXM FAQ) that taking a medium dose of K during a dxm trip will "boost" the trip one plateau higher, like it would turn a second plateau into a third. I think it would be a good way to both conserve the K and stretch out the experience so to speak, because DXM is so long lasting
I tried this last night and it seems to be the case. It isn't as mindblowing as I thought it would be but definitely when you do K on top of a dex trip then it takes less K. With this combo it is very hard to tell where dex ends and K begins but when the K wears off you can tell b/c the dex is still there. It is basically not much different from a K trip except that you don't almost come down to baseline you come down to dex-line. It seems like a reasonable way to stretch out your K because you seem to need less of it to hit the same levels.
I loved K back in my clubbing days (not to club on but I discovered it at a rave) but then when I stopped clubbing I didn't have easy access to it and started doing dex instead.
Then recently K came back into my life and the first time I tried it then it felt just like dex, and I thought it was weird because dex seems like a poor substitute for K after you've done a lot of K. But now that I've comboed them then I can tell the difference just it is a lot more subtle of a difference than I thought it would be.
I would say that when you combo them dex fades into the background, but comes back when the K starts dropping off.
I don't know why so many people are such chem snobs, dex is not a bad drug and just because high school kids can chug cough syrup and it is legal to buy/posses, it doesn't make it vastly inferior to K.
K is a generally more fun but is WAY more expensive and does not last long at all, which may be an advantage if you don't set aside time to trip and just want a few quick bumps before bed, but not so much of an advantage if you want to chill all weekend and do a trippy movie marathon. Dex is not that bad and deserves far more credit than "K's retarded brother" or something.
I like K a lot but given my recent experience I'm thinking I may only want to do it when I'm already robotripping just for financial reasons and also because the comedown is a lot further away from baseline which is good for longer sessions.
I don't know if I've said this too much already but it bears repeating: salvia leaf (not extract) is extremely fun to do when you're on dissociatives. Try it on K, Dex, or Nitrous and you'll see what I mean (some of the best trips I've ever had was on dex+salvia+nitrous)