I took Gabapentin for nearly a year, and had dizziness, tiredness etc, and then really bad stomach problems. I stopped and have been on Lyrica for the last 8 months - I'm on a really low dose (50mg twice a day) but still getting on much better than I was on the Gaba

I hadn't realised how little the Gaba was doing until I stopped it. I haven't noticed any side-effects on the low dose of Lyrica, but when I was on a much higher dose of it 18 months ago, I did have some issues, which was why I was swapped to Gabapentin. In Lyrica's defence, I had the same issues later while on the gaba, and they turned out to be the CRPS, not the meds,
That said - obviously a lot of folk swear by their Gabapentin, so it works for some and not others. Personally I'm much happier with Lyrica, but I know Gabapentin is encouraged more by docs because it is MUCH cheaper for them to buy. Very loosely, I gather Lyrica is an active part of Gabapentin which has been isolated, and that's why the dosages for Lyrica are a lot lower than Gaba.
Bram.