Have listened at Upscale, they are super nice folks. They will do what they can to create a no surprise situation when you take the product home. I listened to some Tannoy (Kensington perhaps) hooked to a Marantz source for streaming and amplification. It curled the toes. The Tannoy was magical.
As a owner of JBL's, in various types, I would be sure that you keep your JBL's. There is a sound that is special to each, the "california sound". I gave one of my son's a pair of 4312's I had, and found I had to replace because of the specific sound.
Look at as much as you can with your ears, using amplification that best matches what you have. Your ears will tell you if you're doing the right thing.