From what I've heard, fluorophenibut is not as good, it's more intoxicating and less euphoric and lasts much shorter.
I've been physically dependent on phenibut a couple of times. The first time I was taking it every day for about a year, 3 grams or so per day, and had to cold turkey suddenly. The amount of anxiety I felt was very high, but 2 days into it I came upon some pregabalin (Lyrica) and found that if I took it every other day, it completely and utterly blocked the withdrawals. After a week and a half I stopped taking the pregabalin and I just had some occasional lingering residual anxiety. Gabapentin and lyrica and phenibut are all gabapentinoids, so they have cross-tolerance and work at most of the same receptor sites, which is why gabapentin and lyrica work well to mask phenibut withdrawal. However, if you go that route, make sure to not trade one habit for another.
The second time I got off phenibut, I was taking 2.5 grams every other day for a few years. I went down to 2 grams every other day for a bit, then went to 2 grams every third day... had some anxious days on the day I normally would have taken it for a bit but then I started feeling normal on those days. At that point I dropped to every 4th day for a few times and then stopped cold turkey. The withdrawal wasn't really that bad at that point. Basically I felt fine physically, and a lot of the time I felt fine mentally too, but it was really easy for me to fall into negative thought patterns or anxiety loops. I had to catch myself when I'd experience those and remind myself that I was just withdrawing from phenibut. Besides that symptom, sleep was quite difficult. I would be able to lay there comfortably, but I just couldn't shut off and sleep. I would eventually doze off and sleep very lightly and have really vivid dreams, which were pretty cool sometimes, but the lack of sleep was annoying. I would take a benzo to knock myself out every few days so I could get some full nights of sleep. It took 2 weeks to feel mostly normal and then I'd occasionally experience moments where it came back for another 2 weeks. All in all, it was pretty easy.