I've been having quite a time reading this forum. I am bedridden with the flu and needed something to do. I am a retired IT manager for a Biotech Corporation.
For home use, the Dir 655 is about as good a firewall/router as you can get, in my opinion. I have configured Netgear, Linksys, Cisco, Belkin and others for friends and they all have their issues. For instance, Netgear routers run quite hot and need ventilation/fan installed.
All this complaining about slow, cutting out, dropping...et al yet not a word about well-known causes of these failures in general. Some of the postings which are desperate, smack of pseudo authoritativeness and deep anger are mostly non-productive.
Try these unmentioned changes before you go out and buy a competitive unit.
Buy good quality, shielded cables. You cannot purchase these a Rite-Aid Drug Store.
Use free diagnostic software, such as NetSurveyor to see if your channels are "occupied." Do not use "auto" channel selection unless your workstations are very close to your router.
Make sure your router is getting sufficient cooling air. Hot circuit boards drop and malfunction. Many routers in plastic cases can use more ventilation or at least highter blocks under them to allow air to pass underneeth. Enlarge cvooling holes or install a fan.
Turn off unnecessary or legaacy features that can slow down your desired packets. Will your network run correctly without Unicast, Multicast, UPnP??? If you don't need them, get rid of their broadcast traffic.
Keep your router away from other electronics.
Do not use the horrible dlink workstation software if you can use MSZero.
Don't use USP netcards (they are slow) unless USB is your only available port. If you have to use USB, make sure it is a USB 2.x port. Make sure USB drivers are the3 latest.
Do intense troubleshooting on your workstations and NIC cards, not just your router. I would bet over half the complaints I see here are more likely on the workstation, not the router.
I have seen incorrect instructions in the dlink "help" and you may rightly question anything you read there.
Avoid gimmicks like SecureSpot. 'Nuf said.