Of all the L/W books I've read that are written accounts by pilots who flew various planes, a large portion of them all of the fondest memories of the 109F series. I can think of 3 books right off the top of my head where the L/W pilots said that the early 109F model was by far their favorite. The 190 drivers who came from the 109 also have high praise for the 190's, saying that it was far, far easier to fly and fight what with all the advanced controls and systems for the age. "A Higher Call", and Osprey's "Fw 190 Aces of the Eastern Front" are two great examples of both of these planes and what I'm referring to.
In the game, each of the L/W aircraft are dangerous and capable in their own way, even the 110/410. I agree with Latrobe for my part, I feel like I can scrap my way out of almost any trouble in the F4, while in the K4 I feel like I don't have to. In the 190D I feel like a Pony pilot, just better looking. All through the 109 series you give away little things while getting other things in return, from the E model to the K4. The F4 and G2 IMO can be fought the most similarly, the G6 is sort of in it's own little world, the G14 being the utility batter of the higher end, and the K4 being the supercar, with all the quirks/vices and advantages that come with that.
If it was a bet for $, and I was going into a furball, it would come down to the F4 or the K4 for me, depending on the details - 5/6 and pick em.