Wow, thank you 1JGC, that summary is the best thing I've read on this after a solid 3 days of researching . . . especially re: the GPS. I hadn't even considered the Pioneer DVD receiver; I'm now debating that and Z150BH. I was most concerned about Pioneer's GPS, but it sounds like they've stepped up their game. And if their maps go out of date, I can always use my phone apps through the AppRadio feature. Sounds like this is the one that suits me best.
I had the z140 in my old car and then installed it into the GC. No complaints and the z150 is supposed to be much better.