Unlike the majority of nice big shiny jets, the average Q400 has to undertake 8-10 lanings per day. Often into regional airfields with shorter runways and certainly in my part of the world into storms, strong cross winds and driving rain (actually the wet bit makes for smoother landings so no coplaints there).
The gear takes a pounding on most of those landings, so there is no doubt it is man enough for the job. That certain publicised mantenance failures and the odd mechanical issue has arisen is not surprising. The Q400 fleet is clocking up sectors as fast as anything else out there, and the average 4-5 yerar old Q400 will have done more landings than a 20 year old 747 by now.
It's all relative. Me, I have faith in them, and I have to trust them on a daily basis. The Q400 is a damn fine aeroplane. It does the job it's built for very well indeed, and is really only hampered by it's need to maintain commonality with the older versions. Shame about that. It really should have been the Dash9, but certification costs would have probably killed it off before they started had that been the case.