I sold my PSR-800, I hated the way it worked, and the "ez-Scan", and even though GRE said there wasn't anything wrong with it, it was pretty deaf. I'm keeping my HP-1, even though it went deaf and is presently at Uniden getting fixed. It was only about a month out of warranty, and I had just installed the extreme upgrade, even though I swore I wouldn't for $100. Hopefully it comes back working like it did when it was new. It was a decent radio then.
I agree as my 800 also seemed deaf. I use a Stridsberg multicoupler for 8 radios. I'll setup the same frequencies in a Uniden and a GRE PSr600 and the 800. The Uniden and the PSR600 would both stop and open the squelch on decent signals as they should. The PSR-800 would just keep on scanning.
But if I stopped the 800 on the channel that the Uniden or 600 was receiving, then the 800 would hear the traffic just fine.
It seemed to be related to tone search. If I turn off tone search and either set the correct tone or set the frequency with no tone then the 800 would also stop from scan mode when the 600 and Uniden did.
Because of this, I can't use tone search mode reliably unless I park the 800 on the frequency I wish to determine the tone on.
It also did not matter if it was a DPL or PL tone or a frequency with no tone, the 800 would not stop and open the squelch if it was in tone search mode. I did find that really strong signals did work in tone search mode.
It works fine on digital channels set to a NAC search mode.
It took me a while to figure this out but I suspected all along that I was missing traffic. Only after I setup the three radios with duplicate frequencies did I learn how much I was missing.
I now regret buying the 800 but decided to keep it now that I know how to work around the problem. Plus it does work very well for an 800 MHz P25 simulcast system here. That alone was enough reason for me to keep it. I just use my other radios when needing to search with a tone search also.