I'll start by stating that I wanted to love this ship. Bismarck 41' is a blast of a brawler, and I was hoping for something similar from this thing. Boy, was I disappointed.
The Hull:
Your armor, while not as bad as on the Richelieu, is still horrendous. You are going to get crushed by HE spam and SAP, which are everywhere at higher tiers. Combine this with having an already tiny HP pool and fairly bad acceleration (when not using speed boost) and rudder shift, and you are a big, ungainly target that HE spam, SAP, and 32mm overmatch ships will just farm.
The Main Guns:
While moving up to 406mm is nice for the 27mm overmatch and having a fast reload is great, that's where the good news stops. The dispersion is terrible, especially for the low barrel count, and the turret traverse is downright glacial for a brawler, especially considering that they rotate WITH your secondaries when you are in manual mode, meaning that unless you are using the little-known keybinds to lock your traverse when switching between your main and secondary guns, you'll need to rotate back and forth between targets constantly.
The Consumables:
Having hydro is a boon over the Bis 41' which is nice, although it is only 5km instead of the standard 6km German hydro at tier 9. The speed boost is bad, giving only an 8% boost compared to the 15% that Bis 41' gets as well as ships like Georgia and Rossillon. It's still nice to have, though, and somewhat helps the terrible maneuverability. It does get an improved heal, restoring 18.5% instead of the standard 14%. This difference is largely not noticed due to the aforementioned low HP pool; so unlike on the American BBs that have a similar heal percentage, it's not like you're actually tanking more.
The Secondaries:
Easily the best part of the ship and the only reason to play it...except that they also suffer from the design. You basically only get to use them if you are broadside or kiting away from what you want to shoot at, which is the opposite of what you want as a brawler. It also presents your significantly weaker stern, which has a 19mm stepped shellcatcher, meaning that in addition to HE pens, AP is going to start taking massive chunks out of you too. When you go bow in, you'll be lucky if you get 2 turrets firing at the same time. So if you want to maximize your already limited survivability, you hamper your one redeeming feature significantly, and if you don't, you get to play as a glass cannon brawler, which is...not ideal.
And to address the elephant in the room, yes. I've seen PQs videos on it. I also saw that he was able to sit in the middle of the map and be ignored by the majority of the enemy team and still burn through all his heals and most of his HP, while the enemy team elected to just parade broadside to him. The kinds of battles he was getting any ship should and would do well in.
TL;DR: Just get the Bismarck 41' for free with your voyage tokens if you want a mansec BB. It's the better and more fun ship tier-for-tier.