the newer expys (16+) have a better and updated sync than the one used on your 15. idk if you have tried it but it is vsstly superior. my dad has an escalade, beautiful truck, my problem is though is that its a vanity truck like all gms. it looks amazing, but its not ppl friendly. the seats are 2 firm, the ride is 2 trucky, interior packaging behind the front row is abysmal, and if you think sync is bad, cue is on a whole nother level. i myself is waiting for an 18 but ford is taking they sweet time to unveil it. i also read somewhere that the navi wont be ready until early next year snd the price will jump exponentially. if the 17s didnt look so dated inside, id get one, but my 09 navi treats me well 75% of the time. after driving both mone and my dads truck extensively, i can honestly say i will never own a gm.