I just watched Harmy's Despecialized Return of the Jedi.
It's a fantastic experience, just like his SW and ESB. However, you can see it is a garbage-in-garbage-out process. The Max Rebo Band scene is obviously from an upscaled and filtered laserdisc master, but since that's the only digital scene that exists, it's either this or Jedi Rocks, and I prefer this 10000000000x's to the jar-jarring cgi abomination that is Jedi Rocks.
Also, I was able to notice where Harmy really got into detail. Vader's eyebrows have been re-inserted, but again, because the only digital scene where they existed is the upscaled filtered laserdisc masters it's not perfect. The whole scene is hi-def, *except* for the eyebrows, which if you're looking for it look a little blurry. It must have been painstaking to cut and paste just the eyebrows in this scene. The Anakin ghost in the final scene is the same situation. Yoda and Kenobi look hi-def, but Anakin is a little blurry. I'm sure if they tried to do this in 1080p instead of 720p, it'd be even more noticeable. Again, I'm purposefully looking for this, so to the casual viewer, they're probably not going to notice.
These are my Star Wars disks now. I will never watch anything else. Lucas can go to hell.