I am in the midst of printing a 45-copy, two-sided job on my 4900. I printed the first side from the paper cassette, but even when I let the paper sit overnight, it still had a slight residual bend from the first side's printing that it wouldn't reliably feed from the cassette. I knew that I'd have to feed the sheets in one at a time from the rear feeder. I thought it would be a drag. I was wrong. It's worse than that.
The first problem is that you can't feed a sheet in too soon after the last sheet was printed, or too soon after there's been a paper skew error that requires you to remove the paper. Instead, you have to stand there with the paper in your hand for a few seconds while the printer decides that the rear feed slot is indeed empty. You have to do that even when it just told you to take the paper out of the slot. If you put it right back in, it thinks the paper was there all along.
The next problem is the dreaded "paper skew" error, which I get about 40% of the time. I have no idea what I do when I load it wrong that's any different from what I do when I load it right. I actually get fewer paper skew errors when feeding C-sized sheets then A-sized sheets, though it seems like it should be the other way 'round. When you get a paper skew error, the printer instructs you to "Load paper properly", as if it's all your fault.
Another unpleasant thing about paper skew is that you can see when the printer has misfed, but it takes it about 20 seconds to figure that out. As far as I know, there's no way to tell the printer, "Give me back that paper and let me load it again." So you have to stand there watching while it decides that the paper isn't loaded right and suffer through the printer pointing its LCD finger at you and saying, "Shape up."
Does anyone know of a sure-fire (or close to such) way to load the printer from the back?
I've had these problems with the 3800, 3880 and now the 4900. My 9800 has never misfed, not even once.