These track specs posted on the web are spot on since they address tracks that are logged within the unit.
62

60csx

The garmin 62/78 will hold 10,000 trackpoints per track. That alone is worth the extra money in my opinion, 500 points doesn't give you enough resolution for longer trails.
Perhaps they need to publish a spec about the limitations of what can be uploaded on a particular model? Not a word about it in the manual.
As a side note, I looked around Garmin documentation for information about truncating at 500 for the 60 series.
In MapSource help I found the following remark:
"NOTE: Tracks with more than 500 track points may be truncated on some Garmin GPS devices. Check your device's owner's manual for more information."
I checked the manual for the 60csx as they suggested. No information there.
