Waddle is faster and the more traditional punt returner. He's going to get all the flashy plays and pre-draft accolades.
Smith is crafty, tough, and plays special teams. I've thought for a while he'd be the prefect pairing with Harry, who can spend more time inside and take over a lot of possession duties, allowing Smith to spend more time downfield. He does whatever it takes to succeed. Hard worker. I'd love to have him aboard.