So as I've been looking at stats of various Hulls in Rogue Trader I saw that some of the Hulls are much better than their counterparts making You pick them most of the time instead those underdog-hulls that are just worse for their Ship Point cost and I'd like to know if You think the same. So here are my thoughts on that matter:
Transports
Jericho & Vagabond - they just can't stand a chance from their latter supplements counterparts, for example Loki , the nearest compatible to Jericho has 1 more Speed and Armour, 5 more Detection and Manoeuvrability, 10 less Hull but instead of Port&Starboard weapons has a Dorsal mount in addition to Prow mount both ships have, meaning he has 4 more Space and Power that would otherwise be used for that extra side weapon that has not that much of tactical use anyway, besides having a Dorsal and a Prow mount means You can focus-fire enemies in fore arc, feat impossible with Jerichos Prow/Port/Starboard weapon layout, and for all that improvements we only have to pay 1 (ONE) more Ship Point, so I think winner is obvious here. Vagabond is a little bit harder to compare as his analogue - Carrack, costs 5 more SP, but if you have money then for 5 SP and 2 Spc You'll get +2 Armour, +5 Hull and most importantly 2 Dorsal mounts instead of Dorsal+Prow on Vagabond, meaning 270 degree focus-fire which is extremely good including how low Manoeuvrability on both ships is.
If You need a dedicated transport and You have means to protect it then Universe is Your best choice, specialized to extreme but it's a unique, niche vessel that otherwise can not be compared to anything else.
Raiders
Viper - Bad Idea, unless You need a ship that can do nothing except scouting.
Hazeroth is superseded by Cobra that has same SP price.
Shrike - the best "true" Raider as it has +10 Det, +1 Armour, -5 Man, extra Turret and +5 BS for only 4 SP compared to Cobra. Whether You are going to be a privateer or a pirate Shrike is Your best choice for a voidship hunt
Frigates
Falchion & Claymore are just pathetic - first one having 6 less Space then even Sword has, lower Det and Man, costs 2 more SP, doesn't even have that extra turret... trading all that for Str 2 torpedoes that on their own won't do any damage. The second one having -4 Space -2 Armour and -6 Hull costing only 2 SP less than Tempest and that is just not worth it.
Now Firestorm is not a bad vessel per se, but it can only be useful if You use that Prow slot right and mount there something heavy like Dragon's Breath Lance, although devastating (2 Firestorms like that can bring down a battlecruiser in a single turn) it is a kinda risky tactic, for You must get close to Your enemy first, enemy who will shoot back while You do that.
Sword vs.Tempest - in low-ordnance fights Tempest is just better - +2 Space, +1 Armour & Hull paying for that with -3 Det, -2 Man and -1 Turret while costing equally and more importantly having the same speed, and if You are up against carriers then again Tempest is better but only if You have money to pay for the xenotech Laser Grid that costs 2 Power & SP to install making Tempest again better than Sword.
Turbulent is IMHO the best frigate there is, it is equal to or better than Tempest in every stat except that -1 Speed, but his only real drawback is that -5 to Command tests that nevertheless still makes Turbulent the best pick of frigates.
Cruisers
Lunar & Ambition , compared to Tyrant and Dictator are just worse, cruiser stats are not that different from one another and that makes comparison pretty simple, as for Ambition - if it would cost 53-55 SP I would probably start thinking, but it's just not worth its money.
So Tyrant & Dictator are Your best cruiser picks, if You need a pure gunboat go for the former, if You don't mind using ordnance cruiser then Dictator is there for You, leaving us with only 2 good hull types compared to dozens of equally good ships in BFG.
Battlecruisers
Armageddon & Chalice - first one having no Space at all, second one blowing itself up because of Plasma Conduits, who would even try to buy those ships?
For Overlord & Mars see Tyrant & Dictator and switch names.
Grand Cruisers
Exorcist & Avenger - first of all having a Grand Cruiser class carrier makes no sense including the fact that there are much less costly though efficient options to do just that so Exorcist is a strange option, while Avenger is a very good fleet gunboat, meaning that if You already have a big and powerful fleet and need an additional "blaster" then Avenger is there for You, in any other case - not worth it.
Repulsive is basically an up-sized battlecruiser and should be treated and used as such, the only problem of all Grand Cruisers is that per RAW when their Hull in battle reaches ~30 their crew is probably already all dead same as morale, and there is no way to avert this, that making Repulsive and all Grand Cruisers in general a very bad choice. Still there is one unique niche for it - there are groups that don't like having multiple ships and are more into having only one ship and gradually improve it over time. For them, Repulsive stands ready, if You take incompetent crew, pick every component as bad quality and don't buy weapons costing more than 1 SP You can lower the price for it to 56 SP while having no supplemental components except weapons.
Would be glad to hear Your thoghts on that matter