I haven't logged in here in quite some time, but saw this discussion and wanted to throw in a few words about my experience w/ NWA. Mirroring what was said in the above post, my product from NWA is down the street at his daycare right now! Our almost-9-month-old is perfectly happy and seems perfectly healthy (e.g. no genetic issues that we know of).
We wanted to try to get pregnant at home, so NWA was a pretty obvious choice since they ship directly to a customer's home. It took us 5 attempts: 3 attempts with the first donor, 1 attempt w/ the next donor, and the 5th attempt (new donor) was our lucky one. That donor had a pretty good track record, but is unfortunately "sold out" at the moment.
We didn't have any issues with customer service - I liked the guy who answered the phone! He was always very helpful in terms of giving me up-to-the-minute info on their donors. We were relatively picky about our choice and we also needed a CMV- donor. I never felt rushed in the process - called multiple times before we placed our first order. The only shipping problem we ever had was b/c of a snowstorm - our shipment was delayed by a day, but it wasn't a big deal.
I know this doesn't necessarily reflect on the sperm bank, and it may not even reflect on the donor, but our son is probably the most laid-back baby I've ever known. I don't just say that as his biased mother - we've heard it from so many people. He's a ridiculously happy bundle of fun!