With the exception of the 2 XS, YT will generally play videos just fine. It's when you want to FF or rewind that the shortcomings appear. The UI is a little laggy on the TV and Stick, but tolerable. But the 2 XS will crash even just letting it play. But remember that the 2 XS is pretty old, and severely underpowered compared to the current models. Your version of the 2 has double the memory and significantly more power. And your Premiere + has double the memory of your 2, and again a significantly improved CPU, even over your 2.
Dan
Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.