First of all, as the person that posted before me said, a lot of the numbers in this thread is inaccurate. I suggest that you, before posting suggestions, check all the facts to be able to present a decent proposal with valid facts supporting it.
Now, for the real facts.
Kaiser: 22/37, can do 23/39 with stripped crew
Nebraska: 23/39
Queen Victoria: 24/40 without armor, 21/35 with armor
Amagi: 23/39
Charlemagne: 25/42 with normal setup
Project 24: 21/35, possible to go 22/37 with absolutely no armor (not even .2 belt), not to recommend however.
H44: 23/39, can be pushed to 24/40, but you have to take of some crew.
Montana: 24/40
Lion 2: 23/39 with all 3 guns on, 24/40 with 2 guns (25/42 possible?)
Super Yamato: 25/42 with very little armor (recommended), 24/40 with more armor.
Alsace: 25/42 normally (with decent amounts of armor), 26/44 with one sailor stripped of crew/removed
SN BB5 with its epically hard to write name: 22/37 (23/39 possible with stripped down crew?)
So, what we can see from the numbers above is that the soviets are generally slow. But speed it not everything in this game, take the Kaiser for example, it's the second slowest of the BB6s, yet it does the best in HAs/HDs (final tile, and yes, my personal opinion).
What the Soviets do have, over all, is firepower. I do not own any soviet ships myself, but from the few times I have tried them out I have been satisfied with the firepower, as well as with the range (45 angle gives a nice boost in range as well). The situation where I found the soviets lacking a little though was in a BB6 game. Playing a Project 24 in a battle with 20+ BB6s on each team was sort of frustrating. The ship might have decent range, but it's hard to use it because of the combination of low speed and bad turnrate. A game where I would have scored 400k+ in Nebbi landed on 300k or so in this ship, and then I was playing it as aggresive as possible, often taking just as much damage as I delt, due to not being able to get out of the enemy's range in time. So, if possible, improving either turnrate of firepower would be nice (I would prefer turnrate, only improving the speed wouldn't help much in my opinion).
As for the BB5 I am unsure, I actually enjoyed playing it in GBs, but then again, maybe that was just bigginers luck...
Edit:
OH speed is calculated by taking the base speed *1.7, and then rounding off to the closest whole number (belive it's called integer in English, not sure...). The list then becomes the following: 20/34, 21/35, 22/37, 23/39, 24/40, 25/42, 26/44, 27/45, 28/47, 29/49. Those are the max speeds of various ships, OH speeds like 38 or 41 can't be the ships max, and you can't go faster simply because you have crap engies. Just a little note for all the people that wrote various fawlty OH times in this thread :)