A very small number of people, listening on certain systems, have perceived a noise or distortion when playing certain content.
The vast majority of M1001 customers do not have any complaint with the sound quality, and are happy with the product.
We are continuing to investigate the issue, however, because we want all of our customers to be happy with the sound!
In answer to your question, if you're using wired Ethernet, then most any broadband router will work fine. If you can run Ethernet to the SoundBridge location, I would recommend doing so. Although wireless works great and I use it exclusively at my house, one can run into problems caused by external interference, building structure, other appliances and so forth that just don't happen with Ethernet.
I use the Belkin Pre-N router at my house. I use it for its excellent wireless abilities, but it's also a capable wired router.