If he's an exciting talent I'd rather we signed him even if it means he may not contribute instantly, rather than an average player that does enough during the next six months but ends up being a burden to the squad over the next few seasons.
I have faith in most players Wenger outlines for the first team, the disappointments are usually the likes of Chamakh, Park and Squillaci who were never expected to be anything more than bit part players.
He does tick the boxes on paper: winger/forward, quick, tall, technique and good recent form in front of goal.