E170/190 departure reliability is as good as the B737/A320 fleets, and probably a bit better as the airframes are newer. The Virgin 737 fleet is aging and its not usual to see one parked due technical.
Embraer seem to build a good aircraft, the EMB 120 is still operating in many regions, some with very high times.
One would think that to maintain good reliability, there has to be good engineering back up.