Pam, I struggled with this one, myself! We had a cheap (as in, lower end model) Graco DuoGlider, and it sucked. It was like pushing a bus.
Then, I bought a used Maclaren side-by-side. It was "meh". Hard to maneuver 'cuz it was so wide.
I don't know...how 'bout we ask Twitter to see if anyone has any more suggestions?!