Merry post-Christmas and a Happy pre-New Year to all!!!

So, I think the REC head unit in the ol' XK is dying a slow and painful death, and I'm researching for a new aftermarket head unit. I've been partial to Kenwoods for years now, but also had Pioneers years ago. So what might you suggest? I want something that has navigation built in. I see that some can download apps from wifi, which seems pretty neat. Kenwood uses Garmin navi. How easy (and expensive!) is it to update maps?