I recently purchased the H4n and conducted the first recording this morning. I simultaneously recorded the signal on both my H4 and H4n, keeping as many variables identical as possible.
I made a sync click at the beginning and end of the recording. The total recording time was 62:30 and this was a 44.1k 16-bit audio-only project.
I placed both files on the Vegas timeline for a 44.1k 16-bit project.
Aligning the sync click at the start of each file and comparing the ending sync click revealed a difference of 1 second and 24 frames between the two files. The H4 file was "longer".
The H4n pre-record was on, but this just meant there was more audio recorded before the first sync click. I was comparing only the time between the first and last sync clicks.
I wasn't syncing these files with anything else such as a video recording, so I'm only commenting on how much drift these machines can exhibit between themselves, something we were all aware of, but I felt this was a pretty substantial difference if I need to use both recorders together.
Hopefully when I get a chance to test the H4n against my video cameras it will be closely timed and most of this error I saw this morning is from the older H4.
At least the recorded file from the H4n has a real date and time associated with it, although it was the ending time, not when the file was started.
And everyone is right, the H4n manual is terrible...

From everything I've heard, the H4n only drifts a few frames per hour of recording time. Like, 2 or 3 frames per hour. I would guess that most of the issue is with the H4. Curious to see what happens when you try this with video as well. I am planning on getting the H4n to use for video work. I seriously hope the drift is as little as I have heard!

Jay there's no comparison.
With my Sony FX1 cameras, the older At the end of 60 minutes the older H4 will drift end of 60 minutes the H4 will be out of sync by 17 frames and the new H4n will be out of sync by only 1 frame.

That's pretty darn good for the new H4n.

Good to know. I'll probably test the new H4n with my also new Canon HF11. Hopefully with good results that I can report soon. I need to do a time-lapse test with the camera. That will be a good opportunity to let the two record for 10 minutes straight and then compare for drift during that relatively short run.