406 Ive owned the Tarapocket its pretty small depending on what you pack for day gear. id recommend looking at a Connor pocket as that is going to be more inline with a 22 inch frame if that is what your using. Connor pocket is going to match up better and give you more volume.
I don't have the Tara pocket, but I use the Tarahumara as a pack and compression panel. For a light day pack it works well, and I prefer it as a panel because it has the slot pocket and water bottle pockets for stashing things. I would hesitate to get the Tara pocket because of the lack of water bottle pockets.