Interesting info, RVF750. I flew Q400s a long time ago but don't remember any reliability issues, apart from the NVH system - but the fleet was new then.
The first one in the UK was G-JEDI, (I think we were the UK launch customer?), and I was one of the first pilots on it. For the first six months, it landed really gently, whatever you did. Then it and the others started giving harsh landings. Positioning as a pax on G-JEDI one day, I noticed that the main oleos were very low, and the poor thing was basically landing on its bump stops. I did flag this up at the time,but nobody took any notice.
After that, most of us learned to land one main at a time, whatever the wind, which softened the landings.
I also remember one day we had a brake hydraulic leak and the "engineer" fixed it by getting a large, agricultural, adjustable spanner and tightening the connection. Hmmmmm, I thought, not really a precision engineer; where's your proper flare nut spanner?