It's hard for me to start approaching this play because I'm not very familiar with Sherlock Holmes in other contexts. I think I saw the movie that came out a couple of years ago, but I could not tell you anything about it. If I were to approach a review of the play, I would focus on the quality of the staging and refrain from comparing it to movies or TV. In general I think that's how I would approach any staging because if you're going to the theater looking for something rivaling TV and movies for effects or subtlety, you're probably going to be hugely disappointed anyway. The stage is a wonderful medium, but it has different techniques and strengths.
What I struggle with most in this case, I think, is knowing to what standards I should hold the production quality. I've been to a lot of plays over the years, but not really to community theater productions in this sense. The smaller theaters at home are all pretty high profile. I'm kind of a theater snob is what I'm saying/admitting.
I would probably focus on the costuming and sets for this particular staging, which I thought were really well done, especially for a small theater. I think it could have been useful to change up a tie or vest or something on the men's clothing to clarify when the play was supposed to move forward a day, but overall the costumes were great. They were intricate and well-made. The sets captured the aesthetic of the time period and the darker lighting gave it all a mysterious glow. It was a creative use of a small space, especially with the way the lower part of the set switched to different settings.
On the other side of things, my most negative response was toward the accents. Only a couple actors could hold theirs (good work, Marin!) and it really distracted me from the action. So I suppose my question there is whether or not it's important for the reviewer to note that this is a small, volunteer-run theater without professional acting and accent coaches. I'm not sure if this should change my overall feeling that the play should have been done without attempting accents.
I think another thing about reviewing community theater, especially in a small town, is that everyone's so much closer than when a reviewer covers a Hollywood movie. The actors are going to read the review and then the reviewer could very well run into them while out to dinner or walking around the city. That can definitely be a good thing, in that it would push me to be very deliberate about my wording and to avoid cattiness on the negative side of things. On the other hand, it also might push me to give a more positive review than I otherwise would have.