I find it easier because I make such big amounts of food - potatoes need to be slightly over cooked though. Never any lumps but I don't rice the potatoes if I'm using them for fish cakes as the consistency doesn't work.
I've thought about getting one but thought its a bit of a faff taking the potatoes out, putting them in the ricer,squeezing them into a separate pan, then having to warm them up.
Its supposed to make better mash but I think its more the potato you choose than the method of mashing. I choose a floury type potato and steam, never boil, then use a metal masher then beat with butter and cream -sometimes soured cream with chives -and my mash is always lump free and fluffy.