They are not comparable: The players they play with are also not comparable. By the time Spezza cemented himself in the league he was already playing with an established veteran team, that had been in the show a few times and was on the cusp of being a cup contender. He had the likes of Alfredsson and dare I say Hossa, to work with. Spezza was a plus early on in his career because of 1. Martin 2.Alfredsson and 3. He had a lot more behind him regarding Fisher a defensive minded 2/3 line center.
We have a young team now, and the balance of this team is a lot different. Chiasson has the potential to be a good power forward with some hands. Will he ever be Spezza? No... but he is young enough to learn how to back check and play a 200ft game whilst getting this team points every second night. Spezza never learned how to play 200ft. We did not keep Martin long enough to drill it into him. Murray let his players play a more free style game... it was great until we came up against the Ducks in 2007 and they shut us down.
Dallas can have Spezza... I am glad that we got some potential young talent for him. An aside: our 2nd round draft pick in this past draft was excellent. Either way, this team is a different team, skates differently, hits differently, exits and enters the zone differently.