I've been a customer of Magic Tailor for at least two years now. The team is very attentive and highly skilled. I've gotten lots of things altered - jeans, skirts, jackets, dresses. Some alterations were simple (i.e. shortening of hemlines) and others were more complicated (e.g., slimming of sleeves, raising of shoulders, etc.). I am always happy with the results. They will even tell you if they think you are just wasting your money and something is not necessary.
I go there quite often and they know me quite well. I'm definitely a loyal customer. I honestly don't think I've gone anywhere else since I found Magic Tailor. That means that if I get lazy and don't get my clothes altered, I essentially don't wear them until after I (finally) make a trip over there.