You will be happy to know that after grinding my ass off in the Mogami I managed to buy the H39. He is mostly stock as we speak but here are my initial impressions about him:
Gun are lackluster: DPM is behind ships like the NC due to less guns and awkward gun layout. Her 16inch guns are the best choice for me: lighter and similar DPM (like only 50 less compare to the 16.5inch guns) while having greater ranger.
Secondaries are nice, though the 4.1inch guns are terrible at damaging anything that is not a DD. The 5.9inch guns reload is bad though the damage and range makes them acceptable.
Torpedoes are gimmicky and for self defence only. Don't try ot use them offensively as they lack the range.
Durability is lacking as well: armour is not the best and he is a huge target.
Speed is his true strength: 25.9 knots stock. She can keep up with your cruisers and hunt down enemy ones.
Overall, not a bad ship but I would choose the Montana and NC over him. However, the idea of a fast hound could appeal to many people. I feel that the H39 will play similar to a battlecruiser in how she plays.
Do you have the H39 yourself? If so, how do you feel about him? If not, do you plan to get him eventually?
Yeah, I've got her. I've found her bloody well nice, except against Yammy's and Montana's. I prefer the 16.5" guns, as they are much punchier. I also dropped the cruddy 4.1" secondaries to save weight.
The armour protection on the H39 can be a bit weird, as when you make the armour optimally thick, your citadel still isn't well protected against American 16" and the Yammy's 18.1" guns, and your fore and aft ends can be penned by continuous 8" fire. Provides near immunity against 14", 15", and 6" guns though.
It's different for different battleships, but generally speaking, battleships of higher technical year will have larger citadels and smaller fore/aft ends. Mid-tier battleships may or may not have a large citadel (depends on the ship), and the low tier BBs should have evenly spread armour.
Two games of the many I had in my H39, which I named Ersatz Raeder. I killed at least one battleship in each game and these were both in Expert. The interesting thing was I killed them with my torps. That's right: I was able to kill ships with the H39's torpedoes.