I liked watching The TV Set quite a bit. And I admired the work that went into it. It's a "behind-the-scenes" movie that avoids what is, IMO, one of the major problems of this kind of movie: that the TV show/movie/play being produced is so obviously unbelievable as an actual TV show/movie/play that any edge the jokes might have is blunted by the show-within-a-show's "straw man" status.
It doesn't quite avoid another major problem of this kind of movie, though: I'm going to call it "Writer Entitlement Syndrome".
So, these kinds of stories have a pretty standard set-up: there's the Writer, who has a particular vision that he wants to get across, and then there's the System, which wants to create an appealing product. Artistic clashes with Commercial producing satirical insight into the process of pop culture production.
If you're a writer and your overriding ambition is "artistic", then you're probably making a mistake if you're trying to write for TV or the movies. You get into this field because you also have a driving ambition for (a) a large audience or (b) money.
Now, it's cool to "fight for your vision" or whatever - that's part of the writer's job - but I think it's just a little self-serving to set up this struggle as the Sensitive Clued-In Artist vs. the Philistines Who Control the Purse Strings.
(Part of the reason that I like the way Extras handles this kind of story is that Ricky Gervais primarily targets the Writer's own ambitions and vanity).
I do want to say that The TV Set isn't terrible when it comes to this stuff: for instance, David Duchovny's writer character has pretty realistic sense of what he's doing. He says of his script: "I know it's not Shakespeare. I know it's not The Sopranos". Still - the movie could have used a little more self-awareness, overall.