The D-Link with it's advanced QOS features helps gamers who are on clogged networks. The only real difference you would see with this router vs other ones is if people are downloading alot of stuff (FTP, HTTP, Torents, ect). This is a nice feature, as until recently to get this feature you needed to look at very expensive routers worth half a thousand.
I would go with the D-Link "gaming" router between these two solutions. However usually I would go cisco, but you would have to buy used without the software, and you wouldnt be able to get one working
Also, you may need to enable bridge mode on your "modem" before you use it with your new router.