In SJC's shiny new terminal, DL and AS are right next to each other. My wife and I showed up with 4 bags, one of which was a smidge over 50 pounds, and one of which was more like 70. This hadn't been an issue with DL of course, but from reading this thread, we knew it'd be one with AS.

I went to the DL counter first, to see whether they could check the bags for us and take AS out of the equation, but no dice. However, they said to just check them with AS, pay the fees, then come back and they'd issue an eCert!

At that point, we decided we might as well check all 4 bags, at $20 a pop. The AS kiosk cheerily took my money. The AS agent then realized that the kiosk hadn't taken any money for 2 of the bags being heavy... but after fighting with her computer for a minute or two, decided it wasn't worth the trouble to charge us.

So we went back to DL with our receipts for a total of $80... and they said that oh, they can only give eCerts in increments of $25, so they'd have to round up to $100. So we came out $20 ahead. But we spent most of it on in-flight food and whatnot.

I was impressed that the DL staff there were able to handle it so quickly - I got "reimbursed" with the eCert before we even went through security! ^^