Jm lab chorus 715 vs 725 and psb silver stratus???

Hi, currently im having a small bookself jm lab chorus 705 which is really good at high and midrange; however, because of the small size woofer, the speakers dont have a lot of bass extension or deep bass. Therefore, im looking to buy a bigger floor standing speaker which could give me a better bottom-end but still keeping the nice natural high and midrange. I went to a local speaker dealer and found myself interesting in jm lab chorus 715 for $600, 725 for $700 and psb silver stratus for $475. All of them in like new, store demo condition. So i need some suggest from people who been using or used them, and how good is the price? Too much or it about right? Thanks