If you’re talking about the Ateret Torah in Brooklyn, it’s sephardi and the Rosh Yeshiva is a very chashuv person Rabbi Yosef Harrari-Raful. It’s a good place from what I’ve heard about it. I know several guys who went there and they have all turned out to be bnei torah.
It follows Sephardic (Aram Soba) nussach and minhagim but has a yeshivish hashkafa and derech halimmud. Rav Raful managed to pull off the synthesis very well.