I've been impressed with the next-day service I've gotten from them in the past, but it's one thing to put an order in mid-May and have it show up on one's doorstep the next day, and quite another thing to put an order in two weeks before Xmas (and pay only for UPS Ground) and have the whole thing show up the following day!
Admittedly, part of this is no doubt due to our having one of the main locations (I think they have three, one in Illinois, one in Florida, and one in North Carolina) in the suburbs here, so the orders don't have far to go to get to Chicago ... but I was still expecting it to take 3-4 days with the "holiday rush" for this stuff to show up, so I was quite surprised with the next-day-delivery!