I have two Rotaries, one about two-years old and one about a year old, and they both perform similarly in that they stiffen up in certain situations.
The viscosity of the lube goes high with low temperatures making it feel stiff. Feels like about -30 deg Celsius here today. Will make anything mechanical hard to use even before you get the gloves on. This is one reason I lean towards the clicky (and with raised switch) at the moment.
eala