Had the first CRJ-900 experience on 7/12 MDW-MSP and was seated in exit row 12D.

The seat appeared very nice with good legroom, etc. Then, started noticing things -- NO recline; shortened armrest on window side (to not block exit door); reduced length seat bottom cushion (also to avoid blocking exit door).

For a flight of just over an hour plus boarding/taxi time, it became very uncomfortable. The reduced length seat bottom made it feel like I was sitting in a rowboat after a while. Don't know if the balance of exit seats are similar, but will avoid them from now on.

On the plus side --
Overhead bins large enough for a 22" B&R rollaboard.
Larger Windows
Excellent Lighting
Overall Headroom (important to 6'-2" pax)

Looking forward to an upgrade next time!

Also, was on US EMB-175 from RIC-CLT last week in Y. A very nice aircraft -- would rate it higher than a -9 in many ways -- even better in NWA's config with F cabin!