I'm researching new subs and I'd like to see what anyone's thoughts were when they finally upgraded to a high quality subwoofer. This may help me decide which one to get. I have two in mind but want to hear what you upgraded to and what the result was. Was it noticeable? How much? Did you have regrets about the upgrade? Would you do anything different now? What were your expectations when upgrading? For the purpose of discussion, I consider my old PSW10 and my current Bic F12 as entry-level subs.