I have personally bought from liveaquaria.com and vividaquariums.com on several occassions, and have been very pleased with the quality of their fish. But more importantly, it is the customer service that drives me back as a repeat customer. I will not do business with a vendor that does not offer good customer service. This is why I will never do business with Saltwaterfish.com.
On the flip side, I've had good customer service from liveaquaria AND vividaquariums. For example, I had placed a large order from vividaqauriams and had a cleaner shrimp that was DOA. I called VA to let them know and without hesitation they first, apologize for the loss, and second, offer a replacement or a credit to my order. VA also QT their fish before sending out and makes sure all fish are eating before they leave the store; they also have a 15 day arrival guarantee.
HTH,
Kirk