I recently rewatched TMP and coincidentely Encounter At Farpoint. That way it´s pretty easy to notice that in the beginning Riker wasn´t that much more then a renamed Will Decker. When did he stop beeing a "replacement Will"? Was it when he grew the beard or somewhen in season one? Or was it more a gradual thing? Side Note: Thank god he lost that "stuck up attitude" he has during Farpoint by the second episode. I always crinch when he dresses down LaForge "Is that an offical report?"...it seems so...well...unusually strict for Starfleet.