Hey man!
As you know, I'm on gabapentin here. I've never tried pregablin before unfortunately.
I will say tho, that gabapentin tolerance raises pretty damn fast. And I had withdrawals after only 4 weeks of taking them daily. The withdrawals consisted of severe body pain (or maybe this was the body pain I had before I started taking gabapentin and just didn't realize how much pain I was actually in until I stopped taking them again). The pain is very similar to the achey body feel of opioid withdrawal. The mental aspect sucked. Everything felt very boring. Although it was not the same excruciating "cry your eyes out" type of pain/bored that opioid or heroin withdrawals can bring, but it was bad enough to immediately make every day feel shitty.
I also had hallucinations, like seeing trails, colorful blobs, dark spiders running around, etc.. I've never had this issue before until I went through gabapentin withdrawals. I'm guessing that gaba B withdrawals could produce delirium or hallucinations.
The withdrawals lasted for about 5 days. By day 5 I was okay but I ended up taking them again anyway. So I'd say tramadol withdrawal was still worse than gabapentin withdrawal, but it was close. The pain & bored & mental depression felt... different, than those same things you get from other withdrawals. Not sure how to explain it because it's a subjective experience. I'd imagine gabapentin or lyrica withdrawals could be pretty brutal if you're on them long enough.