I have a type in the CL65 and just got typed in the 604 a few months ago. Totally different types, and I did the full 21 day course through Bombardier.

There are similarities but there are quite a few differences. In a nutshell, the 604 actually has more limitations, it doesn't have all the redundancies the RJ has-nor does it do as many things for you as the RJ, it does have autothrottles and VNAV, speed mode (or FLC) still sucks, panels are in different spots, electrical is different, the FMS is MUCH more capable, the EFIS is slightly different.