incognition
Bluelighter
I'm sure the stimulation have plain ol' dopaminergic reasons, just like with ketamine and PCP, but that part is luckily totally overpowered by the more sought after effects at higher doses. 
Ketamine also have this swiss army knife aspect. Low doses makes you stimulated, and higher doses.. eh, far from stimulated, except for the "comedown".
But maybe its the wide range of transmittor substances affected that makes the popular dissociatives so nice. MK-801 is supposed to solely work on NMDA, but seems just like a nightmare. But whats "true" affinity for certain receptors and whats funny chain reactions in the brain i'll leave for the experts..

Ketamine also have this swiss army knife aspect. Low doses makes you stimulated, and higher doses.. eh, far from stimulated, except for the "comedown".
But maybe its the wide range of transmittor substances affected that makes the popular dissociatives so nice. MK-801 is supposed to solely work on NMDA, but seems just like a nightmare. But whats "true" affinity for certain receptors and whats funny chain reactions in the brain i'll leave for the experts..
I just noticed this in your post. The word buzz has certain connotations and I wouldn't describe Methoxetamine as a buzz drug. That makes it sound like a plain or perhaps euphoric stimulant. It's not that. It's not mephedrone, it's not speed, it's not cocaine, or anything else I would describe as giving me a buzz. It's not primarily a stimulant, the stimulant effect is probably not due to direct action on the central nervous system, rather it's more likely due to the brain responding to neural pathways being activated which are not normally, although I know next to nothing about this scientific stuff, it's just how it feels to me in comparison to other things I've taken. Perhaps it would be better to call this effect excitement rather than stimulation...
Maybe you use the word buzz differently though.