Hensh i can call it a failiure because it does not have a turret which severely limits its options.
How fast it can swivel around is dependent on a multitude of factors including what kind of ground its on, is it a steep hill, is it a muddy road etc, a turret can traverse regardless of al those.
I could recount all the modernisations T-55s and T-72s received by the 70s but its pointless, most tanks in Europe would fight each others at ranges between 1-3km but typically at something around 1.X km.
Well, we can agree it's nothing to get worked up about nowadays. I primarily love the Stridsvagn 103 because maybe I could have one someday. Only takes one man to operate. That's a conversation piece in any man's car collection, and I'm a dreamer.
True that a turret can traverse regardless of terrain, but you'll want to turn the hull of the tank, too, otherwise you might be extra easy pickin's. Also, with the complexity of traverse and elevation, there's slightly more that can break down when aiming the main gun of a turreted tank.
Every tank has it's strengths and weaknesses, I think the S-tank ran into problems because it was so polarized in that regard. You really either love it or hate it. I think it would have really benefitted from a BMP-like setup with a SACLOS HEAT missile launcher on the commander's cupola. Shoot on the move, at least enough firepower to make a dent until you can bring the cannon around. But that's my 2 cents.
It's like a one-armed rifleman. Bottom line, I think the Strv 103 could accomplish all the tasks asked of a MBT. Again, I'm no expert. The S-tank really benefits from infantry-like tactics, shoot and scoot/ leap frog.