Pro:

• Opens late
• A crazy huge selection of... everything. Instead of stopping at multiple places you can buy them all here--if you can find them.

Cons:

• Merchandise are poorly organised.
• Not particularly cheap, despite the impression you get from the place (organised like a dollar store). But even if they were cheaper, it's not worth the efforts to go.
• Rude staff, particularly offensive base they are only rude to other Asian foreigners: this is rare for businesses in my experience. Even if a person is a racist, they are generally very polite to customer.
• Inefficient cashier system: duty free payment takes forever (45m). You wait in a (generally long) line to pay both prices and tax, after they check your passport with much care. Then you take your receipt and purchases, and queue up a second time for someone else to pack your stuff. This person actually operates on your passport--AFTER checking your receipt carefully to make sure everything has been paid for because the second queue is located right next to merchandise. Here comes the kicker: remember how you had paid taxes art the end of your first queue? Here, they give that tax back to you (usually on VERY small change).

I don't know if I can come up with a less efficient system if I tried... Though to be fair, we went twice, the first time was very slow, but all in one line. That took 30 minutes. The second time was as described above. Maybe they were trying to speed things up by trying someone's hair brain idea.