SS1-SS2-SS3 average, multipurpose
SS4 average multipurpose, good speed, 4F-2R tube.
SS5 slow speed/reload, BB hunter,high speed torp, 6F-1R tube,clearly a mix Hei-average
It's not the worst nation but the SS5 make it in disavantage against US/KM/MN.
For multipurpose you just have to check if the sub can cap the speed to chase BB, but all chaser will have 4 F tube then there are quite equal in power.
Personnaly even if the SS5 is more powerful the SS4 is more easy to handle cause you can retreat and but R-torp in the face.
The SS5 with his slow speed is stuck to a head to head.