I don't think anyone would posit that the TMC sequels are ever quite original. Some, such as the 1990 Leatherface: Texas Chainsaw Massacre III, can be quite fun, but original? Not so much.
This prequel to the 2003 remake doesn't really add much of anything, which, for a prequel, is sort of sad. Sure, we get an "origin" story of Leatherface, but it doesn't really mean much as this film and the remake are virtually identical. Hell, this even has a climatic fight in the meat packing plant, just like the 2003 remake did.
Certainly, the movie's not lacking in gore. Plenty of gore throughout this flick, and more than enough to go around. Related, the special effects are generally pretty good also. Like the remake, there's sort of a built-in grittiness here, which somewhat falters due to the polished nature of the movie.
The cast is generally pretty blah. Sure, R. Lee Ermey has some charm, but the four main protagonists, Jordana Brewster, Taylor Handley, Diora Baird, and Matt Bomer are all pretty cookie-cutter, which, given the expected bleak ending, may well have been intentional. Aspects of the characters are interesting, such as the two brothers on different paths (one's going back to Vietnam, the other is burning his draft card and going to Mexico), but there's not much time to really touch on what makes the characters individuals.
Because the movie takes place in the late 1960's, it makes the film a little more unique. Not much, though, and while the gore is, of course, pretty good (let's be real - if a TCM movie can't do gore good, then why bother?), and Leatherface is appropriately threatening at times, The Beginning is pretty much as bland as the 2003 movie was, even after having previously enjoyed it.