Well, a Joey LINKED to one Hopper can access the other Hopper via DVR My Recordings by just moving to the GRAY bar with the Hopper name drop down menu, and select it, and the other Hopper should be available for quick access. Yes, this is from a JOEY. This is the case with a Joey connected to Ethernet, and another Joey NOT connected to Ethernet in my set-up. All my Joeys can access the OTHER Hopper in this manner without having to UNlink, then Link. You could use that access to view content while it is recording on the OTHER Hopper, then switch back (by pressing Live TV button) to return to the Hopper the Joey is linked to or by pressing the Red button for the TV Viewing Status Screen to select the appropriate tuner for your linked Hopper. Of course this does not provide access to the other Hoppers tuners, but if you set your games to record, you don't need to access the other Hopper's tuners, just the program as it is recording with very little delay (I don't know if the LIVE TV option shows up in this scenario, but probably not), that would seem to be quite a good solution.
Also, anytime at least ONE Joey or Hopper in the system that are LINKED to each other, tunes to one of the big four, any subsequent user who also tunes to the big 4 will access it from the SAME TUNER as the first viewer, meaning that no additional tuners will be used of more than one person wishes to watch the big 4 at the same time. This is similar to PTAT, but not exactly. Anytime one person is tuned to one of the big 4, the big 4 appear as GRAY on your TV Viewing Status screen.