There are a few companies who use ThePlanet's facilities, alongside with using their support services to offer you top-quality dedicated server hosting as a reasonable price. I had a dedicated server from
www.servermatrix.com which is one of the companies ran under ThePlanet.
As for my experience, I would have to give them an A+. All my support tickets and phone calls were answered promptly and professionally. Their network from what I've seen is top-notch. A friend of mine however did experience network issues there though, it was from a distributed denial of service attack. From what I remember, they got him and the other few servers that were effected back online in a timely manner for that type of situation.
Currently I have a server colocated at a data center in Indiana called ColoStore. Due to personal issues and my financial situation at the time I had to cancel my dedicated box, I just couldn't swing the $139/month.