I have (finally) got around to ordering and buying the system for my E91, and it is indeed a fantastic product for the price. I'd say that an anti-glare screen reflector is almost essential otherwise you'll struggle to see the screen in anything other than very dull or dark conditions.
Mine appears to support Android Auto judging by the menu that shows up when the system is started, but I don't have an Android phone to try it. Wireless CarPlay seems to work well, and connects straight away in most cases although sometimes it will struggle to connect and I'm unsure whether this is an issue on the phone or the Andream unit.
I wired the USB cable into the centre console, replacing my existing aux in socket with a dual aux in and USB socket (like those found on newer models of BMW). You can buy these sockets for around £10 on AliExpress. I also fitted the reversing camera, using a wireless transmitter to avoid having to route the wiring into the tailgate which appears to be a bit of a nightmare. Initially this worked fine with the car off, but as reported by some others here it would fail when the engine was started due to the high frequency pulsing on the reverse light (voltage control via pulse width modulation). I remedied this by coding the car's FRM module to disable PWM on the reverse lights - I believe the 5 series has a different module to control the lights although I'm sure the same capability to disable PWM is there.
All-in, for around £250 including the unit itself, reverse camera, USB socket and the wireless reverse camera transmitter, it is incredible value and really brings the functionality of the car up to date. I cannot recommend it enough. The only downside is that trying to get the car's head unit back into place with the additional wiring and connector blocks is a real challenge, although this isn't really a fault of Andream, it's just the reality that there is so little room behind the original unit. I believe the E90/E91 is much more challenging than the E60/E61 here though.