I don't like the too-fluffy ricer texture. I want no lumps though.
The ones I mash (with a properly designed and used) masher are smooth as silk.
Re a fork. One could certainly use a fork...or a mortar and pestle...or even squash them between the fingers ( I believe Martha S would advocate this. She's gotten risque due to all the pot she's smoking with Snoop Dog). But a good masher is the thing