I posted this on Reddit a wee while back, though I'd share it here too :
On my way back from Empire space to pick up my MK III Cobra, I stopped for fuel in the iCourier (great ship btw, my new favourite fighter), and having a browse in the shipyard, noticed the MK IV for sale.
Thought what the hell, and bought it. A-rated everything, 3 gimballed beams & 2 medium gimballed multi-cannons and continued on my way to Widows Light to pick up the MK III.
And... sold it when I got there.
Interdicted by a dangerous DBS and an Elite Inperial Eagle. Had to run from the DBS, and the iEagle gave me serious problems before I eventually destroyed it. 320 m/s A- rated boost and horrendous turning ability vs high rated NPC's being a decent challenge now ( a very good thing), but not much fun in the Mk IV.
Yes yes, I know it's not a fighter, but the combination of no speed and no agility means it's felt unsafe and vulnerable, to say the least. Shame as the hardpoint placement and convergence is excellent. On the rare occasion you can bring them to bear.
So a disappointment really. A MK III with the Mk IV hardpoints? Now that would be quite something.