In what way are they "all behaving badly"? Much more likely to be a problem with your installation than with the receivers....
One HR22 flat out rebooted itself and then said it had errors on it that it was trying to fix. I imagine the hard drive is dying.
The other HR22 is just so slow it barely responds. They're just showing their age (got them in 2008).
The HR24 is also slow, and spotty with recognizing remote presses. I found the "clearmybox" keyword, so I'll try that tonight to see if it helps at all.
The HR34 is doing everything that I've seen people online complaining about - slow responses, pixelated video, and recently it's been hard to FF or RR. Sometimes the counter moves but the picture doesn't. Sometimes when that happens it does RR or FF, but sometimes it doesn't. The other thing it's doing lately is that when it is off overnight and the TV is turned back on, we have no buffer. It just starts up as if we're watching live TV and the buffer never existed.
Another thing that happens is that the MRV has begun dropping clients randomly. I've never had that happen before.
Setup is great - at least it worked back when I moved into the home. New home, new RG6 quad throughout. So I know the home hardware is fine. The fact that this stuff has just started happening leads me to believe that the hardware is finally crapping out. Oh, and they're all on UPSs, so power glitches should be very minimized. We've also had only one power problem in nearly two years and that was two weeks ago.