Ordered a couple 15" and a 13" for work, and the 15" units arrived pretty quickly. Asked when we'd see the 13" and the Apple biz person said they were seeing delays on the 13" units. I configured one on the apple site, and it looks like it's the RAM that's holding things back. An 8GB configuration says 1-3 days, but if you change the RAM to 16GB, it changes the delivery date to 3-4 weeks! What's the deal with that?