[wrxtasy]

1) NO LE on the Shield. Shield has good Android Firmware so Kodi Krypton works well. Then you also have Android TV focussed SPMC as well.

2) Yes I can see the problem then. Although I do see U9's without the A3 lite remote on Amazon

3) Yes the gap has narrowed, especially with powerful devices with good Android Firmware - like the U9. As I have previously posted only issues on AMLogic Android Kodi on U9 is rare VC-1 Bluray Rips having problems and some Kodi Krypton PVR TvHeadend deinterlacing problems also.

4) Niche - Custom boxes with custom Android versions of Kodi, long term are usually not a great idea. Koying's SPMC (Kodi fork) is the exception.

Maybe do as you mentioned before...

Xiaomi Mi Box for easy to use Android TV Apps. It has the best simple Wireless voice remote out on the market, and actually gets Firmware support from Xiaomi. Nougat is coming.

4K HDR Netflix - use your 4K HDR Smart TV.

Then pick your 4K S905(x) LibreELEC or OSMC weapon of choice...

Nicest non HDR, S905 combo = MINIX U1, due to the superb integrated Wireless MINIX A2 lite remote.
Nicest integrated S905X, 4K - experimental HDR capable combo = Vero 4K - also comes with a simple Wireless remote.

Yes Wireless remotes make a big difference to responsiveness and enjoyment for day to day use of any media player device.
Something a bunch of box sellers still fail to understand in 2017, even those charging premium prices.