I've been a fan of Bobson Dugnutt's work for some time, and this fan-edit does not disappoint. The audio and video editing are absolutely professional; only one's familiarity with the source material would indicate where the edits were made. This is a reference standard edit.
There's not much to add, as not too many deleted scenes have been provided for Doctor Strange, but here's a quick rundown on the three main changes:
The dog scene: I really enjoyed this deleted scene when I first saw it, but incorporating it into the movie proper makes it much better. Strange is at about his absolute lowest point in the movie, and helping the dog shows that he's starting on the path back, and in a better way. The old Strange would have never helped a poor little doggo -- where's the glory in that? This is the very start of the new Strange that leads him to Kamar-Taj. The juxtaposition of this kindness with the attack of the street thugs is nice as well.
The courtyard scene: It's an inoffensive little scene; the kind of scene where it could be cut, or not, and no one would really mind either way. It lets me spend a few more seconds in the MCU, and for that it is welcome.
The alternate ending: With this scene, I have less kind words. The theatrical release reveals that the Eye of Agamotto is in fact an infinity stone (which, to be honest, we all knew, but still hearing Wong say it is impactful), and foreshadows the coming threat. The alternate scene is basically just a little joke. Also, the bit about making Wong laugh falls flat, as we already saw him bust up when Kaecilius got beamed up. In my opinion, the theatrical ending is better.
If I may make a rather bold suggestion: One of the things I absolutely HATE in the MCU is when the post-credit scene is just a preview for a future movie. These scenes are a bit nice when first viewed, but upon rewatching adds nothing to the overall narrative, since you're going to see the scene in the next movie anyway. I think the alternate ending here could easily be reworked as the mid-credit scene, replacing the Strange/Thor bit. It's mentioned in the scene that it's been "months" since Mordo has been heard from, and so Strange trying to make Wong laugh feels more appropriate here. It could end right as Strange chuckles upon Wong besting him in the music trivia. Just a thought...
In conclusion, while technically this is a great edit, and I will come back to it at points for rewatching, it does not rise to the level of replacing the theatrical release.