I flew ONT on CO in Dec 2009/Jan 2010. The fares were very attractive (about $100-200 less than LAX), so I decided to trek out there to try it out. CO was flying a 738 at the time. The plane was full, with what seemed to be a lot of first-time fliers.
If I recall correctly, the FAs that were on this flight flew in with the inbound aircraft, and had to return to IAH.
As a redeye, it was brutal -- 1:15 departure, 6:00 arrival (4:00 AM Pacific), and I think the plane arrived about 40 minutes early.
Even as attractive airfares try to lure me, it's just too much of a drive to get out there. Probably great for those who live in the IE.