I've been on gabapentin, pregabalin/lyrica and duloxetine/cymbalta. First thing I will warn you of is that the latter two are hard to withdraw from.

Gabapentin worked a bit for me but at that time I wasn't happy with a bit. I had a few runs with it with breaks in between as for me the good effects lessened after a few months. I didn't gain weight on it but I didn't lose any either (I'm a fatty). I was a bit sleepy and foggy at first but it didn't last long on a lower stable dose. When I was at the highest dose it was there all the time but wasn't bad. ETA: to be honest if it's working I wouldn't knock it. Going up a bit might knock the flares back a little but the side effects may raise too so it might be a case of working out which is more important. It might be that the doc can offer you a breakthrough medication for bad days so you don't feel as muzzy overall from raising the dose.

I tried Lyrica earlier this year as I was told it was better and had far less side effects. It wasn't and it didn't. I gained a dress size in a month and as a result of both Lyrica and Cymbalta I also lost my sleep and my ability to enjoy sex. It also exacerbated my brain fog to the point that I was mentally stumbling over simple things, for example I forgot my address when asked at the chemist! It's hard to know what was Lyrica and what was Cymbalta as both have a reputation for the sex and sleep side of things but the weight and brain fog were most likely the Lyrica.

I wasn't warned about coming off them and the pain docs said I could reduce both by half over a couple of days then come off as I hadn't been on them long. The first week of withdrawal was ok but then I had five weeks of a bit harder to cope with withdrawal. Brain zaps and electric shocks and insomnia were the main issues with the insomnia getting worse and sleep paralysis coming into play which is still happening now. It could be that the insomnia and sleep paralysis would've happened anyway, I don't know. Also what works for one might be rubbish for another and vice versa. I just wish the docs warned people about withdrawal and didn't pretend Lyrica was somehow better for side effects.