Like Step I have flown a number that I was told were hard to land, and more that I was told were hard to land in a crosswind, the Auster and Leopard Moth spring to mind there, never actually had a problem and can only think the people making the comments were not using the correct techniques. Certainly there are aircraft that are hard to land consistently nicely, my worst there was a Commander 1000, you would think it was perfect and it would nearly always land with a thump!