I haven't yet bought an HP notebook before, but I did have the HP Compaq Presario that lasted me throughout my undergrad. I had purchased the system from Best Buy, and it was a good experience, but it was not trouble-free.
I am also looking to buy DV2715nr as I feel its perhaps the best notebook available around for a good value for money. From what people told me, HP has significantly improved a lot and if you want the best Warranty/Customer Service, I would say "don't" get the Extended Warranty from Best Buy or any retailer. Instead get the Extended Warranty from HP directly. Advantages are that HP would fix the product within 5 days, next-day shipping, etc. all paid for. Whereas BestBuy would take 3 weeks (sending out to some third-party company for repairs - I have had this experience with my Compaq). HP's Warranty is slightly more, but you dont have to buy it immediately. There is already a 1 YR standard manufacturer's warranty in place. And you can get the HP Extended Warranty anytime within 12 months from the date of laptop purchase.
I looked up DV6707 - it doesn't have a good processor. I have been using AMD Athlon XP since 2002 on my old Compaq, and it is pretty much outdated. I would say go in for DV2715NR. I am also looking forward to buying 2715 in a day or so, after nearly a month of research. I plan to buy from Best Buy and after 6 months or so, get the extended warranty from HP.
And when you mention you need it for an online business - be prepared for battery draining out fast. Because it is VISTA and it takes in more power, HP notebooks have an average battery life of 2 hours. Read the reviews on BestBuy and everyone has said Battery is the only problem. But you could always get a 12-cell battery in the future. Also, Dell Vostro 1400 Notebook has an amazing 5 hour battery life (Dell notebooks are on sale this week too on Dell.com). Either ways, I would highly recommend HP DV2715NR.