I went to the show room in SoHo for my measurement...

I went to the show room in SoHo for my measurements done the first time around and then for the (free) adjustment / alteration after I got the shirt and had it laundered.

First off: Ask for Paul (Paul, if you're reading this; I'm sorry for the extra work but you did an awesome job). Paul helped me with my original measurements and with my adjustment. He is super helpful and very knowledgeable for filling in the gaps of what kind of customization is available for the shirts and for an idea of what direction to look in for any specific situation you have in mind (for the shirt). Paul was also able to help me with what kinds of adjustments I should consider (for example I was concerned with whether or not adjusting the chest and shoulders would affect one another and he was able to explain how).

When you're using the free alteration, they're not altering the shirt. They're actually just taking your adjusted measurements and making a new shirt for you (as far as I can tell).

I highly recommend going in to one of the showrooms for a fitting, if you're able to. They also have samples of the fabrics on site and more samples of styles (collars, cuffs, etc.) that you might not get a clear idea of from the website.

Proper Cloth Management: I came in today for an alteration without making an appointment and I brought a friend who was also getting a shirt made. Paul was the only person working and there were plenty of appointments lined up. He was very up front and honest about his availability and let us know when a good time would be to come back or that we could stick around and browse until he had an opening. We stuck around for awhile, and long story short: he deserves a raise or a bonus. This guy really looks out for the business.