>And is it just me, or has this stuff degraded the player's responsiveness to IR codes?

It was my imagination. I just now set up my Mk2 and Mk2a units together on the table, one with Hijack and one without, and with a single remote (Rio) I sent commands to both units simultaneously. The result? No difference in response speed, except for a very slight lag on short presses of "MENU/OK", which I understand perfectly as a side-effect of hijack having to wait briefly looking for a long press of that button.

So, no difference, no worries.. whew!
(And to think I wasted 2 hours poking at this on Saturday).

-ml