EDIT:
So according to this thread, this is a Google related change and not Nvidia?
In which case, similar to the banner issue from a previous update, you can get a different launcher (see comments for FLauncher) to avoid it
https://www.reddit.com/r/ShieldAndroidTV/comments/181vh4t/ads_at_full_screen/
My personal experience has been the opposite. I have a C8 so maybe the software is different but I’ve found the settings to be decent, the remote to be far and away the best (magic remote) as you can use it like a mouse. Especially when you have to input something, rather than furiously mashing directional buttons to navigate the keyboard you just point and click. All the apps I use work great. The UI is responsive especially compared to the typical TV that runs Android which just feels like a massive lagfest. The software store does suck! Luckily I rarely use it after the initial setup. You can put apps in whatever order you want and quickly switch between them.