I agree the Dash-8 is spectacular to watch on approach! The gear-under-engines is not the only difference. At night, when you have the best view of the lights, there is a difference in light conformation:
ATR: Strong white light on underside of nose; White strobes on wingtips; Red flasher on top of the fuselage, midway back; highlighted tail
Dash-8: Strong white lights behind props; highlighted tail
At least that's what I see.
The coolest thing is that when the Dash-8 passes by, the props are lit up by the running lights. The plane appears to be wearing glasses!
(And with the gear location, on crutches as well...)