What they use may not be the VERY best, but it's generally good stuff because they don't want it causing more problems than it solves.
I had the Comcast guy out this week. I already have their amp in use. He said I should check on-line to get a 6 or 8-way splitter/amp. They do not carry them apparently. I asked him if he had a specific brand...he preferred and he did not.
I saw one from Electroline and another from Channel Plus. Not sure if one of these is better than the other or if both are poor...
My cousin, who used to work for a cable company, gave me an amplified splitter that is the brand PCT International. It looks nicely made, but I've never used it because my signal level is fine without it.
Just because there is a knob doesn't mean you should turn it.