He doesn’t agree with Chabad hashkafos OR halachos…he won’t eat their shechita, believes that their mikvaos are not kosher, etc. (Probably bedieved, if I got stuck in a place where only a Chabad mikvah were available, he would allow me to use it. But lechatchila not.)
He does, however, agree with me that Chabad is to be greatly admired and respected when it comes to kiruv. And since we travel often, we have seen firsthand the generosity and hospitality that Chabad is known for, and we will always be grateful to them for that.