Okay, so I've posted bits and pieces of this critique over the forum, but I'm going to try and break it down properly here. I think it's clear that certain points costs are wrong, for the benefit of the specific ship (and certain classes of ship, in certain factions, particularly suffer from this). By wrong, I mean not currently balanced properly, usually against the lowest cost, and higher cost (though not necessarily highest) ships. Along with those points costs, certain systems of the game could be tweaked minutely, to differentiate between ship classes slightly, without necessarily changing points costs.
Roughly, in many cases, I found very high armour/hull points to be somewhat overvalued, and silent running/higher speed to be slightly overvalued, with ships that fall into the middle of these categories the closest to balanced.
Escorts are mostly fine, though if their vision range were increased slightly, so as to be consistently above their higher class ships, that would be a tweak that could encourage their use more reliably. Don't be dramatic about it, but something like 1-2K range would mean they aren't going to automatically get targeted, and heavily risk death, just to see a bigger ship.
The biggest weakness I would say is in the light cruiser/cruiser categories. Light cruisers are a little better off than cruisers, for the most part, because they tend to sacrifice high cost things like nova cannon, and more (but not enough) weapons systems, for specialties (like torpedoes/squadrons), and they can use silent running, which cruisers cannot. That said, I feel they could use a tweak, and probably most of them could be cheaper across the board (if certain weapons systems, say squadrons, are found to be too strong, then simply value those higher, and increase the costs of those specific ships).
Cruisers are the most over-priced category for most of the factions, as far as I can tell. If you want squadrons, a light cruiser with 1, versus a cruiser with 1, is typically better, OR a heavier ship with 1 but enough armour and weapons to fight in real combat (or more likely simply more squadrons) is better. Something similar happens with torpedoes, where the multiple attack angles, and stealth, of a light cruiser, make up for the slightly worse weapon system compared to a more expensive cruiser. If you want a special weapon like a nova cannon, cruisers are usually outshone by their battlecruiser companions (though obviously if you want to spam something, cheaper is better), because the BCs aren't too weak in a gunfight to compete with a BC/GC/BB. A couple of cruisers can compete, but you can't buy a couple for the price of a single BC/GC, so then you may as well buy the faster/stealthier LCs for their special weapon systems, or the heavier ship that can actually fight. These problems are all reduced for factions like Aelderi, who are basically paying the increased price for armour/weapons alone, and who have gaps in their rosters weight-wise (so their cruisers somewhat fill that role) but they're not eliminated. I didn't play any Orks, but the amount of BBs I saw, compared to lighter ships (though when I did see lighter ships, escorts and LCs seemed more common), makes me think this must be at least a little bit true for them as well.
The last one is battleships, who seem overpriced in particular for Chaos and IN. Their inability to do quick turns, and slowest speed, without having substantially more weaponry than the BC/GCs, certainly they don't have more of the specialty weapons (nova/squadrons/torpedoes), means they're not HUGELY better in combat, despite the advantages they do have, and they seem to be worth a few tweaks (not huge, I'm thinking in a range of 15-40 points depending on the specific loadouts). Other races battleships (or similar class if they don't have BBs), may benefit from a removal of certain weaponry (Drukkari ships could stand to lose some of their missiles, so that their lance/squadron/etc... ships could be a bit more economical, or just reduce the damage of those missiles across the board), slight stat tweaks, and maybe a few points discounts (certainly Orks are ponderous, and may benefit from adjustments like the IN/Chaos ships). Battle barges also seemed weak, but I didn't get a lot of play in with them, and may have just not had time to get a feel for them. Of course, I believe it's common knowledge that the Necrons need balance adjustments across the board, so I'll just leave it at that.
Battle cruisers, and Grand cruisers, for the most part, while they may benefit from some tweaks in stats or points to keep them balanced in comparison to the other classes, seemed the most widely useful, and balanced, for most of the races I played. Some individual loadouts seemed a bit strange (mixing long and short range weapons seems worse than going all-in on one type for example), and maybe could use a bit more of a points adjustment than their brethren, but as a whole, the classes seemed to have the most useful ship types, and largest number of ships that, as-is, I would say are usable.
TL;DR: Cruisers are the most expensive for what they get, light cruisers seem to be the next most. Battleships tend to be too broad in design, and too slow, to not be overshadowed by battle/grand cruisers, for the races that have those available to them. Escorts might be a little more attractive if they had a small boost to detection/sight range by default, over the heavier ship classes, so that they are a little less vulnerable to fire from large ships when being used to scout.