Having met Francis (the Fish Geek on Fish Tank Kings)...I guess it depends on what you're looking for. Francis is the real deal, and really does try to make sure the animals will survive. If you ever get the chance to see his talk on aquariums in the Middle East, go. You won't be disappointed.
I don't doubt that he knows the fish, and I'm sure the guys on Tanked have a similar staffer. I just think Tanked is a more entertaining show. To clarify, that means I want to smack one of the cast members most of the time, as opposed to wanting to smack most of the cast members on FTK.
In both cases, the problem, in my opinion, is that they're in a business that centers on products on a deadline. It's easy for us to say that the tanks should be stocked appropriately, at a safe rate, because we're not hurt when the client says they're going to go to a different vendor that will promise to meet their deadline. The customer isn't always right, but sometimes, to not hurt your revenue, you have to concede. Is it right? No. The clients should be willing to take a moment to understand the basics of what they're buying, and what it means to them *and* the animals, and how to properly care for them. The problem is that the kind of clientele these guys get don't care. They want something pretty, and have a pretty big chunk of cash to throw at the desire until they get it.
I do have an issue with a TV tank from Tanked. It was probably no more than 8 or so gallons, but they had a few albino red tailed sharks, an iridescent shark, and some other fish that I can't recall. I don't know if they told the client (a kid, in this instance) that he'd have to keep an eye on them, and rehome them when they got too big, and that just didn't make it onto the final cut, but as it stands, I wouldn't have put that many fish that get to be that big in that tank.