I think the key question is understanding what kinds of intents users want to express, and then mapping those desires to an intuitive, easy-to-use interface. If searchers just want to specify a one or two word topic and see all relevant options, then a conversational interface is cumbersome. However, if searchers have specific, idiosyncratic needs, then a conversational interface may be more natural -- and more expressive -- than keywords coupled with traditional filters and sorts.