Does anybody know what the real difference between these floorstanders is apart from £500 in price? I have the R500's on home trial at the moment because my R300's developed a fault. I have the option to upgrade to them for only £350 instead of replacing my faulty 300's. I may well do this because they sound great, but am curious what the extra £500 on top again would get me if I decided to "double upgrade" for the R700's. I know it is ultimately down to what my ears say but I thought I would gather opinion before going through the hassle of boxing everything up again.....