I've hit page three of the thread and may as well chime in with my stats. I did a load of testing of Destroyers and lightnings way back when (maybe 2 years ago now - edit a quick search reveals I started testing them back in 2005) with some more done maybe a year ago, maybe a bit more. I was okay with the Destroyer, 80% happy with the Lightning, ambivalent on the strike after a bunch of games supporting mechanised Guard.
The Lightning I was/am set on a 'Lightning Autocannon' 45cm AP5+/AT6+/AA6+ gun. It deliberately breaks the 30cm barrier and I think thats fair because the beast is built around it. I then cheated with the lascannon, listing them as 'Twin Wingtip lascannons' giving a straight 30cm AT5+/AA5+. The plane was a fighter with no save (it has to jink!). Though I occasionally changed my mind and made it save 6+. Either one shows the effect of manoeuvrability in Epic Air.
The 45cm problems have related specifically to three craft in Epic, the proposed Siam Hain beast, the TK A-10 attack and the Chaos AA4+ 45cm attack (which was its only AA attack).
Attack wise a single stand off 6+ (modded to 5+ on intercept) isn't that hot. Low risk but not in the same leage as the above. It is somewhat similar to the Tau guided missiles bm chaff but here the formation are more expensive by far making it a less than optimum usage, still its something to bear in mind.
The comparison is to a thunderbolt. It should be better at intercepts and worse at ground attack.
Intercepts
Lightning
45cm 5+
30cm 4+
Thunderbolt
6+ Save
30cm 4+
15cm 4+
Clearly the lightning has the edge. Against the things you want to kill you can attack at full force, whereas the poor old thunderbolt has to typically only use one attack. Against things like fighters the thunderbolt does get to go full force - but still has to get close which brings up the synergy with defensive ground flak providing a protective umbrella for friendly craft the lightning can potentially avoid (again here in the game its raw range but in my head its due to doing a wickedly fast intercept). The save isn't really worth much.
Ground Attack
Lightning
Fighter
45cm AP5+/AT6+
30cm AT5+
Thunderbolt
Fighter Bomber
6+ Save
30cm AP5+/AT6+
30cm AT4+
15cm AP4+
A trickier beast. The thunderbolt has the raw firepower but has to close to do it (never actually a problem for me - the stuff a thunderbolt can get is typically isolated by the time they attack). Ironically the fighter bomber rule makes it harder for the Tbolt to manoeuvre during the attack run.
To me its equal, but thats on my expected usage, others reckoned the lightning was 10-15 points ahead in a 2 man squadron.
For these chaps I favour a 3-4 plane squadron. 3-4 for two reasons. One they used to be sold in packs of 3

Two a 4th plane isn't 33% increase in effectiveness over two. Going with 250 for 3 +1 for 75 I think would be fair based on the old experiences (and could even be 225 for 3 +1 for 75 - it all comes down to do you compare against the optimum use of both planes?).
I tied myself in knots trying to balance it against the strike on the same points, though eventually I think I gave up.
I tried range 45cm missiles, but to no avail. Here it is the planes main attack so you can shoot up armoured columns and never get worried by flak. Making it 30cm at least gets some risk back into the equation!
Cutting the development chat this time I eventually hoped for the following to balance with the interceptor. Ultimately I don't think it did, but I think it was close. Of course in a list with very poor AA the lightning is a better bet.
Fighter-bomber
Twin wingtip lascannon 30cm, AT5+/AA5+
Missiles, 30cm, 3xAT5+
Why 3x5+ not 2x4+? Well here this is me modeling the use of typhoons and similar. You didn't hunt targets in cover, but rather stuff on the move (of course having the added effect of making everyone quite timid on the march). In Epic 2x4+ gets 1 hit or 2/3's on something in cover. But 3x5+ gets 1 hit or 1/2 on targets in cover. An important distinction for me and reinforcing its use.
In fact as my hard drive recovery tools slowly dredge up more files from the 3 backups that all bloody failed in the same week (laugh? actually I fell to the floor sobbing) I note I later went for 6xAT6+.
I think this does perhaps make it even adn the one bat rep it was tried in seems to suggest it is, to the extent I've got a note about trying mixed squadrons.
The Destroyer was for me fairly straight forward I tested the following with many other players in several different lists over the years. They have played against ever book list in support of everything from the AMTL to Siegers. Based on the forgeworld model
Marauder Destroyer (Armageddon pattern)
War Engine
Bomber
Armour 6+
3 x Twin Autocannon, 45cm, AP4+/AT5+/AA6+, Fixed Forward Arc
8 x Missiles, 30cm, AT6+, Fixed Forward Arc
Bombs, 15cm, 1BP, Fixed Forward Arc
Twin Assault Cannon, 30cm, AP4+/AT4+/AA4+, Fixed Rear Arc
Twin Heavy Bolter, 15cm, AA5+, 360 degree Arc
Notes: DC2. Critical hit effect, the bombers control surfaces are damaged causing the craft to crash and be destroyed.
Points - 350 for 2.
It is totally balanced design (or at least that's what everyone who played it thought), though points are always subjective and the designs wysiwyg. Though not with mine. As I lost the missiles.
I'm not sure what you are after with the colusus. Historically I thought the FW idea worked on two concepts. the first is the WWII super 'earthquake' bomb. Used to take out bridges, buried bunkers etc. Worked on the principle that shockwaves continue to travel and was devastatingly effective against many different targets (and was a British design). The second is the MOAB a big air burst munition. The first would be in Epic terms a IC MW combo (eek), or maybe just IC, most likely 3bp. The second could fit your concept or using an orbital barrage template. Here though I diverge on grounds of playability. A one shot weapon is interesting but hard to balance when some armies/players kill enemy flak easily and others struggle. You would have to cost it for its optimum use m=which makes it very pricy indeed. If something like 3bp IC is not enough for such a bomb (and why not considering its one big bang rather than lots of small ones, different effects but similar enough for epic surely which goes in for tonnage rather than special effects with bombs) and you have to use the orbital template make it 1BP. If thats not enough make it IC. Pretend its a fuel air explosive maybe. This way a two plane squadron makes gaming sense, you have a reason to bring it back turn two and the effects are horrific but survivable. Other options are availible but I assume you want a two plane squadron which limits things a bit.
Out of interest I haven't recovered my FW books yet, what is its description in there? The asset killer or the big explosion?
Anyway back to the thread, onwards to page 4
