Does the landing gear configuration of an impact (???) on the average hardness of the landing?
Oh yes. Aircraft with trailing link undercarriage (e.g. BAe146 and the ATR series) tend to be quite forgiving. At the other end of the scale is the Dash 8, which has long and very rigid undercarriage legs bolted straight to a very rigid wing. 'Positive arrivals' are the norm, and I've managed only two greasers out of around 40 landings in the last month. They were both on very long runways with light winds - on shorter runways, it's very much a case of right speed and right place.
Silky smooth landings are nice for the passengers (and my ego) but they're not the aim of the game.