It's a good question, and I hadn't seen the link you gave, but to answer your question fairly, here's how I decided.
When I was first looking for a new drive, I initially considered the 500g 7200rpm Seagate that a lot folks here were excited about. While a lot of people were happy and reported great increases in performance, a few people reported more vibration than the stock drive, and a few said their drives failed... so I became hesitant. Then the 'out of stock' issues arose, furthering my doubts about the fast 7200rpm Seagate 500g drive. After doing some more research, it was between the Seagate 500g 5400rpm drive, the WD 500g Blue 5400rpm and the WD 320g Black 7200rpm, and I decided to stick with Newegg.com as the retailer based on reputation. I checked out Seagate's corporate website and WD's website for some insights, and after a lot of back and forth between these drives, (and re-reading Toms Hardware
review,) I came to the conclusion that there was a higher level of Newegg customer satisfaction with the WD500g Scorpio Blue than the other drives. A much higher percentage of users rated it 5 stars (excellent) and a significantly lower percentage of buyers rated it 1, 2 or 3 stars overall compared to the other drives. Based on these user experiences, and the very competitive price ($89 after a 10% email discount) which included a free usb external enclosure - I took the plunge. So far, so good! I don't have anything bad to say about the other drives, since I haven't actually used them, and to be fair, if I had gone for the Seagate 500g 5400 drive, chances are it would have been just fine also. In the end for me... space was a big factor, more than speed. With the drive I got I didn't have to sacrifice much speed, as it turns out.