Heat tech is amazing. It doesn't actively heat up, just keeps your body heat in. So amazing for winter. I have heat tech shirts from 7 years ago and they haven't fallen apart.
This place is enormous with so many floors of clothing. Whatever you want, they definitely will have it, and they also a big section for sales of last seasons clothing.
If you are returning a gift and have a gift receipt. They'll give you the sale price only and not the price it was paid for. Must have original receipt to get full price. Uniqlame.
I love Uniqlo for its simplicity and quality. However, customer service seems to be going downhill in some stores (34th St. and 5th Ave locations). Some cashiers are clueless, rude, and distracted.