I'm a great fan of raiders....and - as pretty much everyone has said - adore the battlewagon. Its fighter cover may be so-so, but 4 wings is still fairly impressive, and the hull 6, interceptor protected hull is as tough as nails.
The common theme with raider ships is that they do extremely well picking on stuff smaller than they are; the battlewagon resembles a half-sized version of a 'normal' ship a priority level larger, and takes apart patrol and skirmish ships very well (where the 20" laser is more than sufficient and virtually nothing can scratch its outrageously tough hull).
This is perhaps why the modified freighter is so bad - there's nothing smaller to attack!
The strike carrier is kind of stuck - for canon reasons - at 4 wings. Not necessarily a problem; 4 wings of fighters that can be launched simultaneously is better than many larger ships.
The problem is the near universal 1st edition weakness of carrier ships - with a few notable exceptions (white star carrier, morshin) where you essentially get the carrier for free, there's no reason to by a carrier over a broken-down point of fighter flights. Especially when the ship doesn't offer fleet carrier abilites.
Now I DON'T think a strike carrier should get fleet carrier. The nature of the design means that it can't recover fighters during a battle.
But the strike carrier itself could do with being gunned up a bit. The particle beams (which offer damn good flak for a ship of its size, by the way) will probably disappear into an anti-fighter trait in 2e, which leaves you with the pulse cannons to compare with other ships for firepower. It is outgunned, but not outrageously (although admittedly by far more manourvable ships). A few extra pulse battery dice would be nicest - especially on the flanks. A couple of missile racks would rock, but are hardly crucial. Its problem is that it cannot take on anything with protective interceptors - I've seen an artemis heavy frigate railgun two to death in quick sucession whilst they simply couldn't hurt it in reply.
32 Hull points is damn tough for a skirmish ship (lets face it, it's not bad for a raid ship). It fails in heavy combat because it has hull 4 and no active defences. As the article succinctly put it, laser-bait. Fortunately this should go away significantly in 2e without anything needing to be done.
Speed - speed I see the point. A Raider ship, by definition, needs to be able to outrun normal freighter traffic or it can't catch its prey. I know it's a rebuilt liner, and getting half again the speed is good, but it still can't keep pace with a trader.
The modified freighter suffers from this even more.
Give it the same speed as a strike carrier; if you can boost the speed of a liner that much, why not a freighter? As to the weapons; they're not bad; they just could do with being combined into one or two arcs (one forward and one turret, perhaps). A slower, more hit-point dependant parallel to the Myrmidon LCV, if you like.
The Nova is good for big games - but not so hot when asked to take on a battleship itself (again, it does far better when facing two raid ships or three skirmishers to when taking on a battleship). I'd happily take the free upgrades from battlewagon to nova when splitting down points, but wouldn't sacrifice two for one. Three for two, maybe.
'Special' Raiders
There are two variant raider fleets - the ghosts of omelos and argent's crusaders
Ghosts - The Extinction battlewagon sacrifices fighter capacity, and a handful of odds and ends (one dice of flak, one troop, a couple of hitpoints) and ups the prow pulse cannons to bolters - and adds a pulsar turret to boot. Much nastier close-in.
The mauler omelos, jashakar, and rah'kahm are Dilgar variants and therefore go play dilgar if you want them....
Crusader - The assault freighter! Now that's a quality idea for a ship...
It's not the most devastating ship out there - since once it's launched its slower and even worse armed than a strike carrier - but nobody ignores 8 breaching pod wings. Ive used them on a Tertius-Tertius-Prefect force before and obliterated it (they'll fetch a good price on the open market!)
An assault freighter would really work well in the normal fleet - and its statline is perhaps a better one to base the modified freighter off - even if that pulls it off patrol level.
The Endgame is quite a tasty ship as well - although it lacks a few hit points and interceptors (although 4 doesn't actually offer that much more protection than 2) has hull 6, is far scarier prow on (yes, it's an actual heavy laser, not some shoddy short-ranged abbai salvage), and whilst it lacks the pulse broadsides (swapping them for some unbeknown reason for some naff plasma guns), it packs a nasty missile broadside - making it a great support ship (especially with fleet carrier as well).
Endgame can stand up to other battle-level ships and it's rather depressing that the nova doesn't - just because youre from a raider race doesn't mean a battle priority ship shouldn't be able to take on either another battle-priority ship or a pair of raid-priority ships. Put a raider nova up against two 'proper' nova dreads and see what happens.