It's usually 2 steps forward and three steps back...... They fix the bugs we wanted squished, but then they introduce NEW ones. Rinse, repeat, get excited about the NEXT generation, so we can get rid of this generation's buggy hardware.
My experience with this......
1. Dishplayer
2. 721
3. 921
4. 622
Same playbook, different hardware....
On the plus side, the timers have gotten much better at handling supersized episodes and changing start times, they are better at recovering from crashes, and the feature sets DO keep improving (HD PIP is nice).
On the down side, my DVI port NEVER flaked out on my 921 (the 622's HDMI port isn't putting out a signal now on mine), and once you recorded a show it played back fine (the 622 has frequent audio/video frame drops). Fix these two MAJOR problems and I'll consider it a "good" receiver.