If I had understood how the financing worked I would have either hooked up my finance a week in advance so I could hop on the store at the em effin stroke of midnite, or I'd have waited out the whole "opening day" rodeo and applied in February for it to be here by March.
Since this was a present to myself for my 45th bday, which transpired in December, I just did the barclays thing the day of the release. Unfortunately my particular approval did not populate to my account until I contacted Apple support. So my order was placed several days after the initial rush.
I'm trying not to be an entitled first-worlder, but the whole barclaycard 0% 18 months is the only reason I went for the model I did (6/D700/16/512).
If I was paying out of pocket I would have gone for the base model and upgraded whatever I could farther down the line.
Barclay did eventually say they were going to put a note on my account to retroactively apply the 0% financing if we do go past 30 days before the charge drops. But it took a lot of explaining. I would think that since they are the only finance option for Apple store purchases that they would be more in the loop about the lateness of Mac Pro orders.