I've tested a few of those at work. They're a good thing for a couple of main reasons: Completely self-contained unit. Simply drop in the dash and attach the GPS antenna. - no more dvd reader in the boot. The unit now supports a lot more colours, so the maps look nice as do the menus. Plus you get the excellent quality of Toyota's sat-nav. Unfortunately, I was dissappointed that the unit, as far as audio, is pretty much the same. The AVS has a few adjustable preset levels, but nothing extraordinary, and the EQ is the same Treble Bass Mid adjustment. *** I'd love parametric in a stock HU. Anyway, its a good thing, but probably insanely expensive.