Let me start by saying that the tailors are incredibly kind and helpful. They were able to alter some of my dresses quite well (doing simple alterations). However, when it came to altering some suits, I was really disappointed. One of the suit jackets, which was originally too large, was know misshapen and disproportionate. One pair of dress pants was extremely unflattering after the alteration, being too tight around the pant seat/hip area.
I spent over $100 on alterations and would say that half of them either do not help or have made the garment worse. For simple hems, I would go to AJ Tailors, but for anything else, I would look elsewhere.