I saw the show from the nosebleed section of the Broadway. I was around 15 or so and still remember convincing myself to like it more than I did.
The main thing I remember was the sets, which were definitely elaborate. There was one scene where they showed what was essentially the equivalent of an aerial shot of a parade transitioning across the stage diagonally from high up in the rafters to stage floor. Showy sets were still big in those days, which is why it beat out Fiddler's iconic sets; more than anything else, its win reflected a lot of money being spent.
Inga Swenson had a nice song in Finding Words for Spring, but the score overall was not very good. Fritz Weaver was fine as Holmes, but did receive a Tony nomination, but it was a great year for that category, so his absence is not terrible.
The show was produced by Alexander Cohen and had a huge advance. Reviews were very mixed (indifferent?), so there weren't many pull-quotes from the reviews. As a result, the big ad in the Sunday Times for a couple of weeks was the declaration that Baker Street was the first show in Broadway history to break the $100,000 gross mark for a week. Even at 15, I remember thinking that they were trying to get potential ticket buyers to forget the mediocre reviews by impressing them with box office,