The way they manage their network behind the scenes can make a difference to how fast it runs, and how responsive it is. This is important if, for example, you play online games where you need response times to be as low as possible.
For most people, most of the time, it makes no difference whatsoever, all you would worry about is that it works, and how much you're paying for it. But for some people ... well, read this thread and judge for yourself.
