For free or 10M it's a no brainer, I'd rather we get him than Osimen. If CR7 goes, he can play as #9 when Martial is not fit, I think he is much better there than Rashford, granted he is slow to play on the wing and Rashford is much better there, but we have enough alternatives for the wings.
He is a good finisher, he is strong (contrary to what some are claiming), he has a very good technique and first touch, and his link up play is very good too. Especially in games when we are facing a low block he could be a great backup to Martial.