I have about 2300 hours in the Q400 at Horizon. We had excellent maintenance and keeping them running was still a nightmare. I dont rhink we ever got better than 98% reliability out of them. There's a reason the fleet is pretty limited and it has nothing to do with it having props...for a turboprop it is fast, quiet,passenger friendly, and capable of hauling a ton. Fuel flows were typically about 50-60% of what I see on the E175, at 365 ktas vs 440. Besides maintenance, main downfall is FL250 ceiling coupled with an absolutely horrible radar (paints heavy returns only 40 mi out).