Since you flatly refuse to carry the Manta discussion over to Disassemble Reassemble's thread - cos, really, the Manta (M) is better than the regular one in basically all regards (I was shown its stats last night, and the only worse one was the higher supply cost) - I guess I'll post some Manta feedback here.
Apologies in advance to Knight Chase.
Just gonna get one thing out of the way first: Why do you compare the Manta to a Falcon? The Falcon is a CRUISER. Sure, a light cruiser. But the Manta is a light destroyer for all intents and purposes. You can't complain that the Manta is worse than the Falcon because... well... it is. As it should be. You're comparing a destroyer to a cruiser.

Please don't do this if you ever want to hear a sensible reaction.
Now then.
The overshadowed “third wheel” of the Hammerhead and Sunder rivalry, the slippery Manta is a midline destroyer that can leave most frigates eating its wake. The ship is comparable to its heavier cousins by its wide shield and middling logistical stats, but differs with its focus on lighter weaponry and a more powerful engine assembly. The Manta's gun mounts are undersized if versatile, but it has the ability to support a wing of fighter craft which amplify its combat potential tenfold. The fast destroyer is let down by relatively low integrity, and a tendency to outrun its own fighters when it activates its burn drive.The Manta is a "fast destroyer", but is really just a light destroyer with a mobility system and higher-than-normal burn speed. You might try comparing it to the Shrike, the high-tech light destroyer. Both the ships have high base speeds, aggressive mobility systems, and fragile hulls. While the Shrike totes a classic high-tech flux grid and good weapon mounts to make use of it, the Manta has only a few small mounts, but it actually maintains a standard destroyer flux capacity for them. It works well with expensive weapons like Antimatter Blasters.
The Manta also has a fighter bay. That makes it kinda powerful, and also very versatile. Granted it lends itself to fast fighters, but what's wrong with them? The Manta can't really put up much of a punch on its own (unless you slap on Antimatter Blasters of course), but can easily augment its weaponry with launched fighters.
With a high base speed and a Burn Drive on top of it, AND a wing of fighters, the Manta is highly adept at catching enemy destroyers and frigates, pouncing from a decent distance, perhaps even using its fighters to lock a target down in prelude to burning in. It has the shield and flux handling to make a meal of small targets, and enough armour underneath to absorb a little punishment from something a bit bigger if it needs to drop shields for more firepower. Let's not forget also that a fighter bay means it can sacrifice personal PD weaponry in favour of full offensive weapons, if it chooses to equip an interceptor like Talons (or the Honeybee from the same mod).
Against bigger targets? You're not going to have much luck outside of kiting and harrassing, and with a system like Burn Drive, that's not hugely great for the Manta to be doing. It doesn't have the punch to deal damage to anything bigger, and its speed becomes less useful against slower and slower targets. The Manta is in its element in smaller fleets as a secondary destroyer, or medium fleets as a pursuit vessel. Or, very small fleets as a player flagship. Have you tried piloting one against some pirate frigs? It's a blast, seriously.
Finally,
do you actually have a problem with the Manta? Or do you just have a problem with the Burn Drive? Because neither me nor Chase can do anything about that. As Soren says, if you have a problem with the base game, go whinge to Alex, not us modders.
Btw, just in case you didn't know - but I'm guessing you did because this entire "feedback" block feels like targetted negative - the Manta is one of DaRa's most popular ships.

Sorry it doesn't work for you, but hey, I can't make everyone happy.