I've tried gabapentin and was on 3600/day for a while -- I can tolerate it. Lyrica was okay but not as good as gaba, and I started gaining weight so I went back to gaba. I'm now on Gralise, a new time-release version of gabapentin. It might be interesting for you with regards to grogginess since it's taken at night with the evening meal and a big part of it is absorbed while you sleep.

For me, it seems basically as effective as the three-times-a-day gabapentin, but I don't feel any edginess as my dose wears off (or if I forget a dose). The max dosage is less (1800/day) so I can still add a little extra gaba during the day if I feel I need it.

Unfortunately, it's a new drug, still under patent and expensive. I'm surprised my insurance hasn't put it on the highest tier of their formulary, but it's on the second tier so it's affordable for me. So your insurance may not have the same generosity.