I would say he's comfortably a top 3 coach, perhaps the best. Really, his worth to our team is quite immeasurable. One of those rare instance where his worth is equal to, or more than a very high pick, prospect, or combination thereof.
In every sport, every fan will nitpick at small details with coaching. Personally, I do feel a lot of Leaf fans criticize a lot of short-term moves (that look bad on paper) and overlook the potential long-term gains...
Though I do have my small qualms with Babcock, I'd surely have a lot more with every other coach in this league.
As an aside, I'm generally quite a pessimistic fan when it comes to management. My post history indicates I was very anti-Burke, anti-Nonis, anti-Wilson, and anti-Carlysle. In fact, I'm still not even remotely sold on Lou or Hunter.
But with Babcock, I am as confident as you could be when it comes to a coach, think he's the real deal.