The thing is, I have never had one of my receivers to do the things you and others list. My worst problem with speed is that on some firmware changes in the last 2 years it could take as much as 8 seconds for it to change channels. I have never had my receiver freeze up like you and others describe.
I have to think it has something to do with the DECAs inline or being connected with Ethernet cables.
I have none of that, no whole home, no internet.
Both of my HR24-100 receivers get the guide up in about 2 to 3 seconds at most and change channels in about 4 to 5 seconds with Native turned on and switching from a 1080i channel to a 720p channel.
I absolutely agree that adding network services is related to the problems with the HR24 slowness. But - I have to think it can be fixed because I've never had the problem before 0x062c. I switched from DECA to Ethernet and that helped when I was on 0x06BD, but it did not eliminate the problem. The thing is - I'm paying for MRV, so I think I should be able to use it and have the receiver work as expected as well. Before 0x66d I did not have any problems - my experience with my HR24 is much like you have currently.