I am a little late to this thread apparently.
For what it's worth, I biked Vancouver to Mexico and had the time of my life. I met many cyclists going the other way. Most of them were wishing they were not. I would say the ratio was 100 : 1 for Southbound : Northbound cyclist count.
On the other hand, I find the feeling of leaving home and heading out into the wild blue yonder all together different than the feeling when I point my front wheel back toward the house. If you live in San Diego and start in Vancouver you will be heading home from day one. This may sound trivial but for me this is huge. I biked across Kansas and Eastern Colorado once from east to west against a howling wind - and uphill (one foot per mile average - you can feel it AND see it) just so I could have the feeling of an endless adventure. The trip was supposed to go from New Orleans to Glacier N.P. but continued on to Vancouver then down to Mexico. It was well worth the struggle for me.
Last edited by JoeyBike; 06-17-14 at 08:25 PM.