Hi anchie! I'm in Seattle! How exciting!
I feel like I've read this same thread before and the requestor almost always ends up being fitted in person and being very glad they finally did so. I'm curious to see how you do with your online haul.
I've been wearing nursing bras lately (hateful things) and I have mostly ordered online for those as they aren't easy to find in wide selection in stores. But I also have been wearing the correct size bra for many years now, so I'm pretty confident in my knowledge of how a bra should feel and fit.
Echoing what others have said, even within the same size and brand, the fit of a bra can be totally different! That's why a human fitter is the best.