I just drove Hwy 9 today, accessing it from I5 exit 199, and going all the way to Sumas, then Chilliwack. It runs pretty much due north, east of 5. Slower, probably, but not busy and peaceful. Decent 2 lane. I'm not sure how long the detour delay is, that might make travel times even. After Seattle, I was really glad to be off I5!