I understand the difficulty pulling the trigger, especially when you don't really know what to expect and if you're 'missing' something going with one brand/model vs another. I just got a used Hsu ULS15, and ohmygod!! I need to hire a contractor to come tighten up the house if I want to let it loose!! Pull that trigger, any of these higher quality subs will perform for you once you dial it in. I think it's highly unlikely that you can determine the differences for YOU in YOUR room without hearing them all, and that's where you're at. I'd say you've probably narrowed down your choices to the point where any of the remaining candidates will make you happy.