As a member of the halfrds team..i can say that the JVC units are very good in terms of function, features and all round sound units......however, we do get a higher rate of repair requests for units bought from us on JVC units as of supposed to any of the other brands we sell.
Now that could either be co-incidence for the way in which people operate them, but i'm more directed at perhaps the build quality!! that JVC 551 u have there is a very good unit...touch screen wiv all the motorised screen etc...but even those have had to be sent off to our repair centre to be sorted out!!
common issues wiv JVC's are skipping CD's or trapped CD's...so the general repair process will be re-alligning the lens and giving it all a good clean inside..tends to sort em out!