I'm not questioning the video aspect, rather the guide on the Joey. It seems to me that the Joey has its own guide software on it because it doesn't allow for custom guides from the Hopper to be used on them. You have to make your own custom guide on each Joey which is kind of a pain because if you want to keep your custom guides in sync, it's a manual effort.That is an excellent question. If the video is all generated on the Hopper and merely presented on the Joey, then that might explain how the Snap can accelerate both. But I believe I convinced myself that the Netflix app runs on the Joey separately from the Hopper. (At least it requires a separate login to your Netflix account.) So, perhaps the menus within an app are generated on the Joey, while the regular menus are generated by the Hopper.
Anyway, paging through the guide on my Joey's showed no improvement after Snap installation.