Each station has its own unique design and flavor. It is exciting to go to a station you have never been before, as you have no idea what to expect.
Metro is clearly not designed for tall people. Escalator hand-rail is placed too low and you have to stretch your arm a little bit more. Plus horizontal bars in the metro cars are placed too low, so if you are taller than 190cm, than you run into a risk of hitting your head.
Speaking of the escalator hand-rails, they still haven’t fixed the synchronization problem between the hand-rail and the escalator ladder. The velocity of the hand-rail is slightly faster, so you have to fix the position of your hand now and then. This problem has been there, for as long as I can remember.
The metro network is now equipped with signs in English and transliterations of every station name. Now THAT is an improvement. As a slight overkill the personnel only doors have the “Staff only” text in English. Why? The doors are locked anyway and an English-speaking tourist would hardly have any business going through such a door.
The metro is dug very deep and a trip down the escalator can take quite a bit of time. Interestingly enough, you see many people pass the time while going up or down reading books and newspapers. St. Petersburg truly lives up to its name of a cultural jewel of the North.
You are obliged to free up your seat for any person that looks remotely like they deserve it. This etiquette goes sometimes into Kafkaesque territory. E.g. once a guy around my age took offense of me taking up a seat and told me to free up the seat for a middle-aged women standing a couple of meters away and not even looking into my direction. He gave me evil looks for the rest of the trip, after I declined. If you want to keep your seat, the best way is to get buried in a book or a newspaper.