Projectivy has turned out to be my favourite launcher for the Shield TV after trying a bunch. It displays only the things I want to see, and has a great deal of options.

A million times this. I was so frustrated with how slow and ad-laden the default Shield launcher was. When I got it, it had no ads and was really snappy. Changing over to Projectivy (or any custom launcher really) fixed so many issues and made the device snappy again.