I think they sound really good,and i dont know what everyone is talking about the mechanism being noisy?They play rewind and fast forward silently on my Sony ES deck.The only thing i can see that i dont like about them is the jewel case they come in,they seem a little flimsy like you should be careful with them or they will crack easy.But as far as the build quality and sound quality of the tape it seems to be pretty good.I bought them online at Total Media Inc.I probably wont buy them again because my Maxell MS Studio series cassette's sound just as good and the maxell's are a little cheaper and easier to find.I was just curious ya know and thought i would give them a try.I will use the ten i bought to record some rare albums on and then go back to my trusty Maxell's(They hav'nt let me down yet)!As far as the Sony UX-Pro they have been discontinued and are impossible to find.The only cassette's Sony make's anymore are the CD-IT tapes you can buy at wal-mart and the cheap HF normal bias tapes.