I had a rather strange mistake with a small mouser part order... I requested, and paid for the cheapest delivery option (post office $7), and they sent it UPS 2nd day air ($20?).
I suspect a mistake with their website order fulfillment software coding, since the invoice showed the 2nd day air, but only charge me the slow boat charge.
I tried to clue them that their system was leaking money, but got a bizarre response, that my order was delayed in the warehouse so they upgraded it to 2nd day air, but that was a BS answer since the invoice I was emailed immediately upon placing the order showed the 2nd day air, so it wasn't some after the order decision to upgrade..
So I got the right parts, faster than expected...and they're a little flaky in that one area.
I will second that Digikey is pretty solid too. and good about customer service.
JR