Moi is more than sufficient for most of what I do, but occasionally I need something to look a little more curvy & organic - filleting usually takes care of that but in the case of constructing compound surfaces, that can take a while & a lot of trial & error. Some of the examples I've seen here just using subdiv are exactly what I'm after

i don't have any specific need for it right at the moment - just asking generally as it's great to have one more trick in the toolbox :)