Stormhawk
The Stormhawk, or Stormhawk Interceptor, is the slightly less retarded and more heavily armed cousin of the infamous flying toaster, the Stormtalon (wing length still the same though). Despite being more practically designed for a Space Marine jetplane, the Stormhawk is by no means original; the Stormhawk has been accused of stealing the ideas of converted and customized Stormtalons due to the latter's retardation. On top of that, it still looks like a GDI Orca, just a Tiberium Wars-era one instead of a Tiberium Dawn-era one (though of course Kane would be the kind of person who could be one of the Emperor's many guises, so perhaps he was just taking a good idea from old nemeses, just like how he borrowed from GDI's superheavy tank boner). This has produced some RAGE at Games Workshop for 'stooping to ripping off the designs of their customers'. (Though really, the only serious problem with that is that they didn't credit the converters. Would anyone be objecting if they had hired them for 'Eavy Metal? Yes, yes they would be.)
The Stormhawk is meant to improve on the Stormtalon by having more frontal armor to cover the fragile cockpit and having a ridiculous array of firepower for a fighter no bigger than a family car. It is also built to be dedicated interceptor rather than a gunship, and is meant to excel at aerial superiority - a position that the Stormhawk can apparently only be comfortable with after almost every other space marine aircraft was nerfed to only be effective against ground targets. So, in typical GW fashion, you need the damn thing now. Oh, wait, since fighters can't shoot effectively at ground targets, you actually need both the Stormhawk and the Stormtalon now.
Tabletop
Ranting and accusations aside, the Stormhawk boasts respectable stats and firepower. It has Front AV 12 and the same Ceramite Shielding as the Storm Talon, but lost strafing run and hover in exchange for the increased agility of supersonic. It comes stock with TL Assault Cannons, a Las-Talon (basically a Lascannon with twice the shots at half the range) that can be exchanged for an Icarus Stormcannon Array and TL Heavy Bolters that can be upgraded to Skyhammer/Typhoon Missile Launchers (Typhoon negates a lot of drawbacks). It also comes with a new piece of equipment called the Infernum Halo Launcher to re-roll failed jink-saves. The Stormhawk can be kitted out to either pump out a lot of shots at mediocre AP or fewer but stronger high AP shots. Unfortunately, it is only BS3 against non-flyer/skimmer units now, thanks to the new flyer rules. You can run up to 4 in a single FA slot, without needing to keep coherency, unless of course you wanted to.
The 8th edition version of this ripoff conversion made it actually cheaper to field with a slightly better payload. It's a dedicated flyer, so it lacks it's potato cousins' anti-ground capabilities in exchange for a default airborne weapon, and the inability to fly low. New rules allows it to shoot 3 different weapons at 3 different targets at the same time. Let's remember, this fella has 2 dedicated anti-air weapons, and 2 fixed assault cannons plus a sweet Anti-Air bonus. However, it can still be fitted to hit anything in the air, as well as on the ground AND after moving, with only a -1 BS penalty. The only other penalty is being forced to move a minimum distance to keep from crashing, though most land-based shooters will have a -1 penalty to BS because it's Supersonic. Overall, it's a slightly better Land Speeder.
Battlefleet Gothic Armada 1 & 2
In Battlefleet Gothic Armada 1 & 2, Space Marine Stormhawks are your standard-issue fighters. It has the same stats as the Fury Interceptors, so there is nothing much to talk about this fighter.