There have been some more recent discussions about Canada 3000 on the Air Canada forum:
http://www.flyertalk.com/forum/Forum5/HTML/002364.html
http://www.flyertalk.com/forum/Forum5/HTML/002494.html
http://www.flyertalk.com/forum/Forum5/HTML/002639.html
http://www.flyertalk.com/forum/Forum5/HTML/002853.html
If cost is all that matters, then Canada 3000 is clearly the best option. But beware of their 28" seat pitch in economy (I don't know if their business class is available yet to LAX) and sometimes less-than-reliable schedules.