As requested on the US post:
Yubari: Basically a Tsukikei that trades 20% of its main battery for some torps. It's only advantages over the DD are higher sailor count due to actually having T slots, and more useable displacement. Slots are inadequate in both size and number to run as an AA ship. Good only for ASW and blitz.
PCL Dhonburi: Something of a fun ship. Like all PCLs, the large number of support slots is counteracted by only having 2 armament slots. Small size, but poor firepower. Mounts 2 of either 8" twins or 6.1" trips. No scout to take advantage of the range.
PCA Asama: Unlike many other PCAs, this does not have its own guns. The 2 twin BB1 (12.2" L or 14" N) guns are something of a joke, as it generally can't hit much with its spread. It's primarily used for its T slots, which support either limited TW capability or modest AA with the excellent 4.7" Type 10A
PBB B65 Project: This ship is something of a contradiction. While most PBBs were intended as leveling ships, the best thing this has is the AA, which is best classed much later. The 12.2" trips have good range for their tier, but rather lackluster spread and low damage. It's barely adequate as a run-and-gun ship, but is best used as a mini-Yamato with the excellent AA battery. Not really recommended for leveling if you don't have IJN AA gunners ready.
EBB1 Mikasa: This is purely a fun ship. Its twin 12" guns have good range for their tier and fire faster than some 8" guns, but they hit like feathered pillows, and with only 2 turrets, it probably has the worst damage output of any BB in the game. It is relatively small, relatively fast, and one of only 2 EBB1s with PBB supports, but is not a competitive ship.
EBB2 Haruna: At level, it's nothing special. The Ise/Fuso have the same supports, similar level requirements, and more of the same guns (14" L). However, if you have BB3+ gunners, this can mount the Nagato guns with 2 binds and the same fire control, giving you almost a proper BB3 at BB2 level. Nagato gun rules apply: 16.1" Type 90 recommended for its armor pen (you can't afford AP with only 2 binds), but weighs a lot. So Type 3 if you want or need to save weight.
EBB3 Mutsu: This is a Nagato with 1 more support slot and better FCS, giving it excellent accuracy. It offers little else and is not generally recommended, as Hyuga is just plain better. But if you can aim, like the Nagato, and maybe want to practice for the Shinano, it's a very good ship.
EBB3.5 Hyuga: This is an Ise with Nagato guns, and has, since introduction, always been in contention for best ship in its class. The gun setup (2 fore, 4 aft) is a bit awkward and takes getting used to, but the 16.1" guns have good range, hit hard, and (in the case of the Type 90) have insane penetration. As usual, Type 90s are recommended to put the fear of god in UK AWs. A fun alternative seup is the Mikasa guns, as this has enough slots to actually do damage with them, and can easily go 45+ knots with such light weapons loaded.
EBB4 Musashi: Like all of its tier, it's just a regular BB4 with an extra crew slot and some more displacement and DP. That makes it a good ship though, as the Yamato is a beast, and it's good for leveling crew up to BB5.
EBB4.5 Shinano: Like most of its tier, this is a fun novelty ship. Unlike most of its tier, the Shinano is an amazing and deadly ship in its own right. The practically block-shotting 20.1" twins have high shell damage and good reload, and if you can aim, this can quickly devastate most opponents even if it usually fails to kill them outright. Only having BB4 supports is only a slight hindrance, and this can still be played with AA if desired, but is not so great as a leveling ship.
EBB5 Mikawa: I present you a Yamato without AA. This has only a bit over half the AA battery of the other Yamato series ships, and is more on par with the barely adequate Asama PCA there. The main bright spot is it can mount the Shinano's 20.1" twins while getting more supports and higher speed. This alone makes it a powerful ship.
ECV1 Hiyo: This is a Junyo that has 2-3 more planes and CV4 supports. The extra support slot - something you usually have to go a further 13-16 levels to get - makes it more versatile than normal CVs of its tier and good for grinding. Otherwise, nothing special here.
ECV2 Katsuragi: Basically does to the Unryu what the Hiyo does to the Junyo. Unfortunately, it still only gets CV4 supports, so this is less of a leveling boon than the Hiyo since you get something strictly better just a few levels later. Still of some use, but not a big deal.
PCV Zuikaku: This is basically a full step up from CV5, with significantly more plane space, more takeoff, and CV6 supports. If you're running IJN CVs, you owe it to yourself to get this. It will serve you well. However, do note that it was completely shafted compared to other PCVs in that it has only 8 small gun slots that are awkwardly grouped. This limits its ASW ability in normal rooms and can be a serious weakness in CV rooms, where most non-IJN cvs can easily outgun it if they get close.