This is fun. It wouldn't be if it had strayed too far from the Holmes persona or if it were not a good movie. Holmes is a favorite from childhood, and odd take-offs on him are generally not appreciated. I have settled on the Jeremy Brett series as the definitive version, but enjoy others that are well done. To me, with remakes and other versions, if the piece is well done, it is not only acceptable but enjoyable. With remakes, I don't know what's worse - it being a general flop as a movie or their changing it all around and calling it the same thing. Sometimes, both happen. Usually, if you like the subject matter, you will probably like a good adaptation, if a bit more inventive that the source material. The Seven Percent Solution movie was well done and enjoyable.
I haven't seen a lot of Robert Stephens, but have appreciated what I have. I looked him up and found that this was pretty light fare for his experience. This is a quality portrayal by him, and the others do a good job as well. The overall production is pleasing. The Dr. Watson portrayal mystifies a bit, that here and in other things, they make him sort of ditsy. That doesn't fit the original stories, nor what Holmes' temperament would seem to tolerate as a companion or assistant with his careful work. Maybe it came from the early Rathbone series with Nigel Bruce. Whether intentional or not, he nearly always had a bumbler quality to his portrayal.
This is a worthy production in all aspects, which I would think garnered some critical approval at its time of release. I can see why it would take the public a while to adjust to seeing Sherlock Holmes as presented here. But, it speaks of the film's overall quality that it has aged well.