8.5 out of 10 I had the privilege of seeing this at the Castro Theater in 2015 for the public world re-release at the Silent Film Festival there. I had no idea what to expect since the film had been lost for nearly 100 years, and I have never been a huge Holmes fan (but I don't dislike the character at all). As we know, silent films can sometimes move at a snoring pace, so I kept my expectations low.
This film really surprised me with its Mystery Comics/early Noir kind of feel- splitting the film into "to be Continued...!" type of segments, since it was originally a serial. I imagine it can be enjoyed watched in 3 separate parts as well (it wasn't meant to be a 2-hour sit-down affair).
The pace is great overall, only a little sluggish at first with the introductory part of the plot (a letter scandal or sorts?) being very outdated. After the first part of that serial you will feel right at home (or Holmes!) with all the booby traps and laughs. William Gillette absolutely steals the show every time he's on screen and it is no wonder that he was adored for his portrayal of the character at the time of release.
I won't give away any of the gags or trickery, but they are top-notch and this film has Chaplin-inspired hoodwinking all over the place. If you enjoyed Chaplin's Essanay work like "Police" or his work on "The Adventurer" then this will be right up your alley.
Going deeper, this film also provides a fascinating insight into the development of the modern "Super Hero." Sherlock Holmes was in many ways the world first superhero, his intellect being the primary superpower. It's kinda neat to think of how this protagonist archetype has developed over the last 100 years! A fine gem to be preserved for future generations :)