Welcome to Houston.
CO offers great flexibility in routings, download their electronic time table then slect "more" for conections and you'll see what I mean, and that's just for starters. I often go through FLL to get to EWR. I've also been successful with doubling back through IAH going to EWR, i.e. IAH-FLL-IAH-EWR on the outbound.
If you're interested in NS only then CO offers 777 service with BF seating from EWR-IAH.
Drop me a line if you want.
SteveHOU