From an ATC viewpoint, I often find I have to treat regionals differently to the 'bigger' jets.
Putting aside 146s, which are not great performers in any area, the CRJ/ERJ families are indeed no slouches when in the cruise, but they seem to be able to go up OR forward, not both. Climbing mach numbers seem to be in the range from M0.5 to 0.6, and then an acceleration to M0.75-0.77 in the cruise. Compare this to an MD80-90 or 737 which will climb AND cruise at M0.74+. This big difference in climb vs. cruise for RJs can make for some interesting catch-up scenarios for the unwary
