Agree with Ouluckyduck, I would dislike teacher recommendations intensely.
I have a son who always seems to fall below the radar and not get noticed - he is quiet, well behaved, and doesn't push himself forward. I was warned by his nursery teacher to watch out for this, and it has proved true! I think his teachers frequently underestimate him.
We can cater for this outside school - going to lots of extra lectures, courses, etc - which he loves. It would be terrible if he were penalised because of his personality not his brains. (not saying he's Einstein - just saying he is brighter than he is given credit for).