I assume that you are really thinking so. However, you may use other words to expresee this meaning. Too many guys have ever used this point to obviously disguise their virtues. I'm afraid that the adcom would have some instinctive disgusts.
In addition, don't forget to carefully measure your tone. Remember that it is a recommendation letter, not something the candidate write himself. Is the recommender close enough to notice this change? At least, how it notices it?