I made "riced" potatoes last night, with cream cheese instead of butter. Yumm! I tried boiling them whole. I don't think it was worth it. It took much longer and the result was no different from my usual method (boil, drain, heat to remove excess water).
Also, a quick tip for those who use ricers. I don't peel my potatoes before boiling. I put them in the ricer with the skin. As long as you aren't putting too much at a time, the potato will all squeeze out, leaving behind the entire peel in the ricer. Scoop out, add more potato and carry on. As soon as you finish mashing the potatoes, run the ricer under water, to remove all the potatoes bits. They will come right off while they are still warm. However, if you let them dry, it will be a pain to clean all the holes.
Including clean up, it took me less than 5 minutes of active time to make my potatoes (I do something else while they are cooking, so I don't count that.