While maybe not all the scenes and digital enhancements to The Exorcist were winners, when judging them it is best to keep in mind the things that were thankfully still left out. For example:
1.) At the beginning when Father Merrin is still overseas, when the clock stops suddenly, there was originally a line where Merrin said, "That clock is broken! Damn!" This line, thankfully is still omitted.
2.) When Merrin stands opposite the evil idol as below 2 dogs fight, there was a considered and abandoned digital enhancement. In the enhancement, when Merrin looks down at the fighting dogs, both of the dogs heads were suddenly CGI'd over with the heads of Delta Burke - one the skinny Delta, the other the heavy Delta. This was abandoned when Friedkin admitted that logically or even symbolically he wasn't sure what it meant. Ironically, the old desert dweller who Merrin spots in this sequence was played by another Designing Woman - Dixie Carter.
3.) Originally there was a scene meant to foreshadow heavily Father Karass's death scene later in the movie. In it, he visits his mother in her apartment and tells her that for her own good she must move out to a hospital. She refuses and he throws her to the floor, throttling her and punching her yelling, "Get out of here! Get out of here!" before leaving by throwing himself out her window.
4.) When Regan comes down to the party in all versions of the film, she urinates on the floor. In the full version of the scene left on the floor, we cut from the shocking shot of Regan's feet as she pees on the floor directly to a shot of the maid's feet as she dumps on the floor where she stands and then we pan up to her startled and embarrassed face. This is in fact what we later see her trying to clean from the carpet with such chagrin.
5.) Left cut out was the scene where the film director goes out the window. Originally left in, we see that the butler, enraged by the man's Nazi accusations twists the guy's head around and hurls him from the window thinking that Regan is asleep the entire time. Upon his leaving though, devil/Regan walks to the window and says, "You know they're gonna blame this on me. D'oh!"
6.) Still gone are all scenes featuring Chuck McCann.
7.) A note of interest is the fact that originally, whenever Father Merrin was feeling ill he was supposed to reach for his bag of M&Ms. However a product placement deal could not be struck with the makers of the candy (the makers of M&M were worried about their product being tied to either the devil or the Christian Right) and so instead we now see Father Merrin reaching for his little box of Altoid mints whose makers eagerly grabbed up the chance at placement exposure.
8.) Also carefully edited out was a third "wacky" black priest at the exorcism, Father Bob, who was meant to bring comic relief and break up the tension when it got too unbearable. This character's key phrase, "I aint going in there! That bitch is crazy!" was even intended as the films marketing tag line and the studio hoped would become a catch phrase they could plaster over all sorts of merchandise.
9.) Also cut is the scene where Father Bob says, "I'll get that devil out!" and then pointing a pistol at Regan's head. Karass at this point backs up, hands raised and says, "Whooa Nelly!" before Merrin smacks the gun to the floor with a deft blow. After this every time Regan did something bizarre (turning her head, spitting pea soup, sneezing) Father Bob would punch her in the face.
10.) In the end with Father Bob cut out, this also meant the cutting of his exit. Following Karass's plunge from the window, Bob shouted out, "Wait for me!" and leapt out the window after him and then running away down the street with a 3 Stooges "Woo woo woo woo!"
So again, give thanks for small favors this film could have been a real mess.