Just thought I'd chime in here and say that it seems that, when learning commands from other remotes, I've had the best luck by holding the donor remote's button down for as long as it takes for the sony to flash 3 times. The manual does not tell you to do this, but it seems to 'learn' best by doing it this way. I've had some buttons that I didn't do this way work sometimes, but not all the time.

Also, I was able to program two sequences onto a single key, just as you could with the older sonys (like the 600), by quickly pressing the buttons on the donor remote(s) one right after the other. It took several times to get it to take both commands, but it's worth it to be able to fit [power on/off] and [tv input 'x'] onto one button. The device-specific a,b,c,d buttons work great for this.

I'm still not sure on the button layout. There are some things I really like, but one thing I don't is the transport (vcr) buttons are too far away from the volume/channel buttons. I thought the 600 had these buttons a little too spread out, but the 620 is definitely worse in this respect.

At first, I thought I'd be returning this remote, but I've decided to take some time to get used to the new layout and I haven't any show-stoppers so far...