I’ve had an 8-shot, 18” non-A1 590 with ghost ring sights, and it was a good one. I got it for about $200 on consignment at my LGS 15 years ago.
Later on, I replaced the original stock and forend with Magpul furniture, which I think was an improvement, particularly with the shorter length of pull. I think they sell A1s now already wearing Magpul furniture and a sight rail, so if I was buying a new one, I’d probably go with that and maybe put an EOTech on it, although I think it’s a lot more expensive that what I bought. If you see something with regular furniture on the used market, you can sometimes get a Magpul set for a little more than $100 if you do some bargain hunting.
[Ive had an 8-shot, 18 non-A1 590 with ghost ring sights, and it was a good one. I got it for about $200 on consignment at my LGS 15 years ago.]