Guess no one wants to try my suggestion.. A simple reset of everything including the swim might help.
Doubt it would help with the problem I was having - I have 4 receivers, 3 of which were acting up - one of which was fine. Just so happens the one receiver with no problems does not have an auto-record, and the other 3 did. Removing the auto-record cleared up the slowness. This follows a clear pattern that I don't think a power cycle would resolve. Especially considering the problem started following a firmware upgrade (0x66c) - it is clear to me the problem is firmware related.
I have separately reset everything from the SWM (by removing the power inserter) to pulling the plug on the receiver, to resetting the Internet Connection Kit, removed the Internet Connection Kit entirely, ran a "Reset Everything" on my HR24, etc etc.
Considering others are also having success by removing Auto-Records too - I think it would support my case that this is the problem and caused by a firmware bug and not something that a full power cycle would fix.
If I start having problems again - I'll definitely consider your recommendation.
BTW- 0x66c also introduced "Far in Advance" which provides some guide data up to a year out. I wonder if this is related to the Auto-record issue - maybe the "Far in Advance" data increase guide data significantly causing the Auto-record to take significantly longer to search or maybe it just causes the Auto-record to hang on the Far in Advance data.