I've taken two formal gowns here for alterations. Both times the gowns needed some significant size adjustments in various places ... both alterations were rather complex. I was pleased with the work both times, and the dresses fit like a glove afterwards. She's a little on the pricey side so I don't take her things like basic hems and such, but it's worth it if you've got something that requires a little more skill and that you want done by someone with experience.
Pros: Skill & experience
Cons: A little more expensive than average, slightly longer turnaround