Opinions on Azelaic Acid?

Ever since I’ve heard of the effects of azelaic acid I’ve been in the search for a product. There are not a lot of products containing azelaic acid (compared to other active ingredients) on the market but I had the opportunity to test two. The first one I’ve used was not so good for my skin since it burned and flushed my skin (even though this ingredients target redness and irritation) which was probably because of its formulation (the cream had cristallized which was shows that it was not so stable). However with the second one I’m using I can see why this ingredients is being talked about a lot lately. Overnight it controls my redness and irritation and helps slightly to exfoliate my skin and clear out my pores. What are your opinoins on azelaic acid? Have you ever tried OTC azelaic acid products?