I've flown Embraers from PHL to BUF a few times...single seat on one side of the aisle, two seats on the other. I find them very cramped foot-wise because the curvature of the fuselage interferes with the amount of foot space on the window side. That being said, just fine for the short 50 minute flight.
The one issue is baggage. You cannot expect to be able to take a standard size roll-aboard carryon, at least on the flights I take. They are all valet-gate checked before you head on to the plane. Bag is tagged, you get the tear-off 'check stub' and leave it at the door. They are then loaded in the hold, and after landing everyone lines up in the jetway waiting for your carry-on to come out of the hold. It can add some extra time if you need to make a connection.