IF you dont care about the OEM buttons and look then I would check out alpine, pioneer, jvc, kenwood units as well
after market headunits can also control steering wheel controls too. So you don't loose any of that functionality
I mean you can get an apple play JVC headunit for $850, uses apple maps or google maps so no need for ongoing map subscriptions.
If you dont care about apple play, then there are units for around $400 which have Dual phone bluetooth, touchscreen, direct USB, siri eyes free, pandora, screen mirroring (android or older iphones/30 pin) from $400
they also support new lightening cable iphones too, but not screen mirroring, just USB audio and Siri
they have better specs as far as audio features too.
I dont see any audio features listed such as preamp output, preouts, eq, time alignment, x-over etc (if you care about that sort of thing) on the OEM units
Android Audio and Apply Car play units im sure will wipe the floor with most headunits out there now. Brands such as Alpine, pioneer now implementing them into their higher end models, but should flow down onto mid range models over time. The downside is that new tech is always expensive
Car manufacturers are also going down this route with using apple car play
the cool thing is, the aftermarket headunits run their own software for radio, CD/DVD etc as they always have
then they can switch over to android audio or apple car play (basically using your phone) and mirroring it onto the screen with full touch control and voice activation!