IMO most people seem to look first at the routers in general, not just the 4500, speaking any router. It's the first thing on the line they look at and expect to always work. For the most part they do. Its when external, user configuration or ISP problems that people fail to understand and realize that sometimes those issues can make it look like the router is the problem, when it really isn't.
Never under estimate user error. Even in yourself. To this day I find myself commiting a technical gaffe here and there. Calling a router a modem, confusing the ports for pop and smtp, saying megabyte when I really mean megabit. Point is, never take anyones word for anything. Not the ISP's, not the manafacture, not even this forum. Use all of us as a source of information, but only as a part of your continued research. In the end, you bought the product, and there for it belongs to you. Unless you want to return it, its up to you to get it to work.
More on topic, I have been quite happy with my DGL-4500. But look around. Check out the simulator for it. Read the reviews on Newegg, Tiger and Cnet. Just have realistic expectations. It will not make your internet any faster it is direct to the modem. It will not decrease your lag. It will not protect you from viruses. No router (in this price range anyway) will.