For me there are 3 plateaus to gabapentinoids. Level 1 is what you get when prescribed and slowly titrated upwards to the target dosage: Nothing recreational, maybe slight sedation. Level 2 is a moderately high dosage without tolerance and feels like being drunk. Level 3 is the full experience and - as far as I remember from 10+ years ago - feels like a stimulating dissociative, maybe a bit GHB-ish.
I never took gabapentin though, only pregabalin, but they are supposed to be fairly similar. Tolerance is an absolute bitch, if you take the same dosage like yesterday you'll experience diminished returns already. Might be just me though, for some the therapeutic effects seem to/must last.