I've had an HR20 for nearly two years. In that time I've had to hit the reset button about half a dozen times. Certainly it has been less reliable than the Series 2 DirecTiVo it replaced, but it reboots for a software upgrade about as often as it locks up.
I can't speak for the HR22, but the UI on the HR20 is about as fast as the UI on the HDVR2 running 6.2, and lots faster that the HDVR2 running 3.1.1c. A reboot takes less than 5 minutes.
Activating a DirecTV DVR purchased from eBay is a crapshoot. In general, you can't do it if the previous owner owed DirecTV money. If he didn't, you usually can.
There's a difference between needing help, and just being plain ole' lazy.
"You cannot teach a man anything. You can only help him find it for himself." Galileo Galilei (1564-1642)
HR20-700 with 2 TB, HR22-100, HR22-100, HR22-100, HR23-100 all running 0x5cd and networked.