i had xm installed by the dealer,,i think they use vaistech,,,,but the quality of the sound is great with the ML system,,i had an after market from best buy in my previous vehicle (delphi system in a chev avalanche,,,ac delco sys) the downfall that the vaistech sys in the lexus has is not being able to show the name of the song,artist, and channel simultaltaneously,,,like the delphi one did,,,,also delphi let u see what was on the other channels b4 u change it,,lexus wont,but the discreet install and sound make it worthwhile, i recommend the vaistech cuz i dont have any experience with factory interactive,even though install is pretty expensive,i was too scared to do the install myself,,not too well with hands-on,,,,,,,so i had to have dealer put it in,,but i dont regret it,,,i have always liked xm,,happy shopping,