Tier 4 Destroyers
Isokazes are a tad slow, but stealthy with the usual great IJN torpedoes. Identical to play to all other Japanese destroyers - sit outside your 6.1km detection range and fire torpedoes invisibly. You're a ninja!
The USN Clemson was my favourite; upgraded to 8 x 4" guns, allowing it to dogfight with even Tier 5-6 destroyers and burn down ships with gunfire. The first true gunboat, and has solid 5.5km torpedoes to give flexibility.
The VMF Izyaslav has flatter more accurate guns than the Clemson with similar dps, but the turret arrangement, traverse and its 5km torpedoes are slightly inferior to it's USN rival. I am starting to prefer its excellent high velocity guns over the Clemson.
Tier 4 Cruisers.
I did OK in the Karlsruhe, but regard it as a steaming bag of poop, strictly inferior to pretty much everything else in Tier 4. The rapid fire destroyer-size guns on the Tier 2 Dresden are not so charming at Tier 4.
The IJN Kuma continues the "heavy destroyer" theme started in the Tenryu, swift with good torpedoes and rapid fire guns.
My pick for most effective is the Phoenix - pretty much a Tier 5 Omaha at Tier 4. Quick, tough, and lots of dakka, with decent range guns. Another very good ship.
Tier 4 Battleships
Myogi. Initially I hated the randomness and ineffectiveness of the half-dozen big 14" guns (majority of which face the rear) but I quickly grew to enjoy the speed - charging behind friendly destroyers on the flag and monstering enemy cruisers, before fleeing the scene, having stirred up sh1t and attracted half the enemy team. My favourite in game moment - dodging the torpedoes then running down a Minekaze (which was chasing our carriers) and blowing it away with a point-blank salvo.
Wyoming. Basically, double the guns, more armour, but only 20kts of speed. Much easier to play than the Myogi but far less interesting and challenging - once you commit, there's no backing out as you don't have the speed to flex. I won't be going further up the USN line as they don't get faster until Tier 8 or something. Quite easy to get 50K+ damage; just get in as close as you can without being torpedoed, and angle your hull, tanking damaged with the "T" consumable.
Admittedly the game doesn't look this good... ...but it does run on pretty much any computer...
Tier 5 Destroyer
Nicholas. Statistically the worst destroyer in T5, but I found it my most successful due to its multi-role nature - a rapid-fire, agile, dogfighting gunboat capable of torpedo attacks. There are two viable loadouts - the B hull has better maneuver, AA and dps but has low velocity guns which "float" shells at long range, whereas the A hull has slower firing, yet more accurate guns.
Gnevny. I enjoy it but struggle to do well in it - as it plays nothing like a destroyer and more like a cruiser. Great guns have terrible traverse, meaning you have to plan moves in advance like larger ships, and it's 4km torpedoes means attacking with them tends to be suicidal unless well planned. Staying end-on to enemies at ~10km and using steady curving zig-zags avoids 90% of shots while keeping your guns on target. Resist the urge for
Minekaze. An excellent destroyer and better than many T6 ships. Fast, agile, stealthy with good torpedoes. It refines the IJN destroyer concept of fast, stealthy torpedo-ninja to a new pinnacle.
Tier 5 Cruiser
Konigsberg. A classic glass cannon with great accurate guns that outrange most ships at it's tier, but it falls apart if you give it a harsh look. Deadly, but needs careful ship-handling. Decent torpedoes. A massive upgrade from the Karlsruhe.
Omaha. The classic spammy light cruiser - good speed, good guns. Easy to use and do well in. Has two viable loadouts - one with better gun range, the other with more torpedoes. A very good ship, but is overshaodowed by its premium counterpart, the Murmansk. (Same ship, in Russian service, is twice as agile and has better torpedoes. It's like the game's developers were Russian or something...)
Furutaka. The first 8" gun cruiser, it has terrible dps/RoF and low gun range (why would a 6" outrange a 8") but precise fire with good penetration. Reviled by most of the player base, difficult to use, but has it's moments and gives a different flavour to the other T5 offerings. 10km torpedoes are a novelty. I found I had a lot of success after I got the 'feel' for it (after about 20+ games, admittedly).
warships today track those stats, making it easy to improve your play.
Tier 5 is where it's at....
Pretty much every ship at Tier 5 is decent, but by now I've decided I do not enjoy lumbering battleships and have no interest in carriers. At tier 5-7, gameplay improves and team mates are (slightly) less like braindead potatoes, whilst there isn't so many "leet" players you can't have good games. Tier 4 also had many excellent ships, but tends to end up in Tier 5 games quite often. Whereas Tier 6 seems worse off in a different way; their ships are similar to Tier 5 but face higher quality opposition.
I've learnt a lot since my Tier 2-3 days, and I've found a lot of "hidden" controls and tactics since then - which I'll have to share in another post, as baby is asleep and I can sneak off to bed....