It was a year or so ago that I came off Gabapentin so what follows is approximate.

Max dose was, I think, 2700 or maybe 3600, built up to gradually say over 3 months, held for 3 months and then back to zero in another 3 months all in parallel with high dose of amitriptyline. No sense of addiction or withdrawal symptoms at all. Don't remember doses of pregabalin, but same general pattern. Dry mouth with both, otherwise no side effects (and no beneficial effects!).

My NP/mobility problem, in legs, is a consequence of damage to spinal cord.