Oregon has 20,000 points so I've never come up against an issue with it.
On one of my really long tours, when the track was about 400 miles long (and straight - the Main/Rhein trip so not too squiggly), it took a bit longer to rotate the map you were viewing if you did a sharp corner so I tend to split them up into about 100 mile sections for when I'm bike touring (which is probably two days for me) but that's just for ease of use and means I can delete them once I've used it.
