In some cases the difference between a Cannondale and the like and Santana, Co-motion or the many others listed above boils down to things like
- fit: more choice in sizes, including a custom option
- couplers: if you want S&S couplers, you can get any steel frame and have it retrofit, or get pretty much any steel frame built custom with them, or get an aluminum frame or CF frame, from one or two places that will actually do those materials with CF.
- design specifics: we were looking for a bike designed for loaded touring. This narrowed it down substantially.
To the original question, Santana and Co-motion make many models, in a relatively large range of sizes, and they both offer custom frame sizing for a relatively modest up-charge. We considered them but concluded we could get full custom for the same price or thereabouts by going with either Rodriguez or Bilenky. And Bilenky is a tenth as far away.
If I had found a Cannondale that fit all my requirements, I'd have probably gone with it. And saved a pile of money.