Yeah, I switched from a Shield to the prior gen of Apple TV 4K in part because the Shield was often laggy as hell (also the UI layout was a mess, also the damn ads, also it was significantly buggier) and AFAIK that's about the most powerful non-Apple box on the market. ATV's way better on that front. Frankly a low-end-but-not-quite-bottom-end Roku machine feels snappier and more-reliable than the Shield did (though not as good as the Apple TV)