My 2 cents to add: AFAIK Belz preceded Lubavitch in kiruv in Europe and My Rebbe bemoaned the fact that changed.
I heard an apparently true story joke recently although I can�t personally verify for obvious reasons. Still the point is illustrating at least. a certain Rosh Yeshiva forbade his bochurim from learning Tanya. So they prepared a list of a few prakim for the RY to look at so as not to waste his time and still make an honest assessment. The next morning they asked his opinion on it. �It�s all about Hashem but where�s the Torah?�
For the ignorant, Tanya references many many sources brilliantly but doesn�t spell them out in footnotes, as The Alter Rebbe sufficed with a brief explanatory note in the beginning that is a collection of sources (apparently they knew more sources back in the day). But that actually isn�t even the irony.