I am currently using the D-Link Gaming router and like it. I had this one and the Netgear one that THG recommended. THG said the Netgear had better wireless. Based on the Netgear package, you'd think you could surf a mile away with it.
I have a difficult wireless setup in my 3 story house. The router is in the basement in one corner and I like to surf in my bedroom on the third floor on the opposite corner and side of the house. The signal goes through solid concrete garage floor and kitchen besides being on different levels.
I found that the D-Link router gave me a better wireless connection than the Netgear one with the smart extended range feature. My personal belief is that the Netgear had an internal antenna and the D-Link had a larger than standard (5 dBi I think?) antenna. At least it had a bigger antenna than my old D-Link 624. From what I've researched, the more powerful the antenna, the better and LOS (line of sight) does matter.
As for which router does the better routing, I don't know. THG says that the Netgear is better with lots of simultaneous connections, but I don't think that really applies to the way I use the router. Also, if you don't have anyone else sharing the network at the same time and you don't have any other web access apps running, I'm not sure you'd need the gamefuel feature. You can always physically plug in your cable to the gaming machine when playing games since many ISPs now use DHCP instead of static IPs attached to one MAC address.
As for bit torrents, I don't use it, but did see somewhere (manual, box or router configs) that it supposedly did give it priority. It also claimed priority to certain VOIP, too. Of course, this is the manufacturer's claim and I haven't been able to confirm it.
Bottom line, I'm happy with the router. I bought it to improve my wireless range foremost and for playing CSS. While bouncing one to two-three bars upstairs, the connection has been much more reliable over the DI-624. If your ISP isn't fast, it won't matter how good the gamefuel is. It only controls variables within your own network. It's hard to say how effective the gamefuel is. There are so many other variables. Honestly, the best improvement I saw with CSS was when I changed LCD monitors from an older NEC 16ms to a 6ms Samsung and that was only slight. On Friday, I am building a new E6600 rig with 8800GTS and 2GB 800 RAM and am interested to find out how much it improves my scores over my P4 3.0, ATI 9800 Pro, 1GB PC3200. I'm only an average CSS player.
Another thing to consider is the mess of 2.4Ghz spectrum. You could be suffering from interference from within your own house, neighbors, or some big ass microwave tower nearby. I have a video baby monitor that completely knocks out my wireless connection no matter what channel I use. If you want to fork out $99, you can get a 2.4Ghz Wi-Spy spectrum analyzer that will tell you everything you need to know about your local interference.