"A £400,000 buy is something that is not usually associated with Rangers in terms of buying players in modern times but what a return they have had when you consider the goals he has scored," said McLeish.
"He has defied his critics. He has failings in his game - they all do - but when you look at what his strengths are, they more than make up for it."
Boyd will be a key figure for Scotland as they approach the home stretch in Euro 2008 qualification Group B. He scored an opportunist opener in the 3-1 victory against Lithuania and having cultivated a reputation as a home-game specialist, Boyd could have Scotland's European Championship destiny at his feet when Ukraine and Italy visit Hampden Park.
"He has his qualities like the rest of the strikers have but it comes down to us picking the right guy for the right game," said McLeish.
"He is a young guy who has improved certain aspects of his game and will continue to do so. What we have to be careful with is that improving his weaknesses is not to the detriment of his assets. I'm sure he can improve other aspects of his game without it affecting his main strengths.
"He is maturing all the time and any time I have read his interviews, he is never one to hide from criticism. His answer is by continuing to score goals and he has never lost that belief in himself."