Basically, what you recruit is what you'll have his entire career. Try and make sure he's versed in at least 1, if not both, of your sets. Try to redshirt him. Anything you gain during the season, will be lost in the offseason.
I recruited a 4 WE player, who is currently a redshirt sophomore. His IQ's are B/B+ (came in knowing the defense). Even his high potential areas barely improved, but he did score 3.7 PPG on 41.5% shooting (44.2 from 3) in 15 minutes backing up the SF and SG spots (natural SF). Also had 2.6 REB and 1.1 AST. A very good bench player, who I won't need to start until his senior season. He's improved 19 points on the season, the only category that improved more than 2 was stamina (3 points).
They can be useful, but make sure his ratings are good enough at the time you recruit him.