They're the same quality IMO, just choose which one sounds best to you. If you find one that sounds nice like phonesdirect.net, or fatwhore.org then go for it. There really isn't much difference, but I tend to go by what sounds smoother and easier for users to remember (usually with rhymes as stated above). Only because alot of brands that have been built on .NET and .ORG domains usually send alot of direct visits to their .COM alternative by the less tech-savvy user.