Thanks for the response. Hopefully we'll get more data from others, and form some semblance of a consensus, because we can't expect good info from the seller.
I have a 400ah, 384ah (bought 400ah) and 200ah 12v batteries. I had issues that caused voltage spikes and balance issues. I replaced their BMS with a 130amp Bluetooth and added active balancers. I have not done offical capacity testing but I have drawn them down 10kw at one time without getting below 12.8v so I'm pretty happy for now. I, unlike some people, lucked out. I doubt these batteries are anywhere new, they lie. If you remove the plastic yellow boards, you will discover all sorts of scary things like missing plastic that is normally found on prismatic cells.. The pictures they show on Amazon don't have any white goop all over the batteries.. The battery tester they use to show it's a "good battery" is for Pb, car batteries. I'll never buy from them again or recommend anyone to do the same.