See The Awesome Practical Orc Who Was Painted Over In DESOLATION OF SMAUG
Above is Bolg as you'll see him in The Hobbit: The Desolation of Smaug. He's the son of Azog the Defiler, the pale white orc introduced in An Unexpected Journey, and he's actually in the book The Hobbit, where he plays a role in the Battle of the Five Armies at the end. You'll notice that Bolg is CGI, just like Azog.
Here is Bolg as he appeared on set:
That's Conan Stevens under that make-up. He was also originally cast to play Azog, who was also painted out of the movie. You may know Conan as The Mountain Who Rides in Game of Thrones; he left that show to shoot a trilogy of movies in which he will not appear.
Design-wise I don't even know how it's possible to argue that the CG Bolg is better looking than the practical Bolg. CG Bolg, like CG Azog, is kind of generic-looking, a fairly boring orc. The practical Bolg is absolutely awesome, his skull held together by metal bands and his big, red beard adding a splash of bloody color to him. The CG Bolg has studs in his head, indicating he also has a fractured skull, but they don't have the power of those bands. CG Bolg is also wearing less armor, losing the bulky authority of the practical design.
Here is a GIF of CG Bolg in motion, giving you a better sense of his design.
Bolg was likely a casualty of the decision to make Azog CG in the first film; as his son and as a character who has a dialogue scene with Azog, it would be weird to have a real orc talking to a crummy CG one. The only option, I guess, was to make them both crummy CG orcs. But in a larger sense Bolg is the casualty of Peter Jackson's new aesthetic in these movies. While there is CGI in them, the Lord of the Rings films are among the most tactile big budget blockbusters of this century; the use of bigature models, prosthetic make-up and New Zealand's stunning landscapes gave The Lord of the Rings movies a sense of reality. You could go there. You could meet these characters. You could encounter these villains.
In The Hobbit films Jackson leans much more heavily on CG, disconnecting the whole trilogy from the original films. The Desolation of Smaug features a distracting amount of green screen work, and many of the great New Zealand landscapes feel like background plates, not an actual location. It isn't until the company gets to Laketown that we enter an environment whose presence reminds us that MIddle Earth was once a place we believed in, not a computer generated fantasyland.
Some people have wondered why I'm so down on the CGI in The Hobbit and yet love a CG-drenched film like Pacific Rim. I don't hate CG. It is a tool, and when used well it's a good tool. For instance I appreciate Guillermo del Toro's decision to animate the Jaegers and Kaiju in his film, as opposed to mocapping them, which gives them a similar feel of pleasant artifice as you get from traditional stop motion animation. I don't quite understand why Jackson, whose WETA Digital is one of the premiere FX houses on Earth, never seems to use CGI that well. We can go back to Return of the King, where the Battle of Pellenor Fields is jammed with dodgy CG and shitty compositing. That same compositing issue haunts parts of King Kong - which also has CG work that is beyond next level. Desolation of Smaug has that green screen problem again, which led one friend of mine to wonder if Robert Rodriguez hadn't been advising on the thing. At this point I wonder if shitty compositing of live action and CG elements is actually an aesthetic choice that Jackson is making. If it is, I hate the choice.
This, to me, is one of the many comparison points to the Star Wars Prequel Trilogy, films whose reliance on CGI and green screen created a jarring aesthetic schism with the original trilogy. The two trilogies simply don't look like they take place in the same universe, and The Hobbit films don't look like they take place in the same Middle Earth as The Lord of the Rings.
Beyond the look of it all, Jackson's reliance on CGI has allowed him to succumb to his worst instincts as a filmmaker. I look at the Barrel Chase in The Desolation of Smaug and wonder what the death of Boromir might have looked like if Jackson had the ability to achieve that same kind of over-the-top, over-complicated CG action scenemaking in Fellowship of the Ring. You can watch as CGI slowly takes over the Lord of the Rings films, and I sometimes wonder if Fellowship, the film with the fewest big CG set-pieces, flourishes as a result.