I have been able to stow my Zuca Pro (www.zuca.com) on almost all CRJs and EMBs. I often get stopped at the door because they do not believe that it fits, but it does (in a few cases, only just, as evidenced by light scratches on the metal frame - but that just gives the bag a well traveled look).

Disclosure - not connection to Zuca other than a very satisfied customer.