Didn't like it at all. 30 minute show consists of 5 minutes of owners daughter yelling at him and rolling her eyes, 10 minutes of people walking around and BSing in the shop, 5 minutes talking about the absolutely exorbitant amount they charge for reinventing the wheel. Maybe 10 minutes of actually talking about guns. Pretty much no time is spent on the actual manufacture of the guns (some of this may be a "don't do this at home" idea, but why even have the show then?)
I think the most egregious exclusions I saw were failing to actually discussing the laws behind some of this stuff. How about informing the audience that not any guy with a shop and machine equipment can just start altering firearms? How about explaining to the audience that you can't just go to a shop and pick up a suppressor?
Edit: to add, they did acknowledge that a shotgun has been mounted under an AR before, but very little about it, then basically acted like they were reinventing the wheel. Also, why the heck do they need a high capacity semi-auto shotgun for a breaching device? It is a 1-4 shot proposition and certainly doesn't require split second follow up shots. I am not well versed in Law Enforcement tactics, but how often do domestic SWAT squads breach a door with a shotgun??? They are supposed to bring suspects in alive if at all possible, using a shotgun to blow a door off its hinges or blow a deadbolt sounds like invitation to collateral casualties.