Okay, first off: "Vastly"???? Try "Marginally".... G-2 has a radius of 636 ft, G-6 has 648 ft.
Secondly: The K-4 isn't really the benchmark. It has a nice sustained climb, but in a combat situation you're not sitting on autopilot. You have zooms, you hang nose-high below best climb speed, etc. The 109K4 isn't nearly as much a UFO as half a dozen other planes in the game, several of them having "Spit" in their name. It is by no means an unstoppable monster. The extra horsepower also adds undesirable low-speed handling qualities that can get it killed if a 109K pilot puts it in the wrong part of its envelope. I think the K-4 is best only if you consider that in the mindset of chasing down late-war monsters with extra speed. Outside that, while I find all 109s capable, I don't see the K-4 as the best overall.
P.S. The G-14 outclimbs the K-4 in most areas below (say) 8-10K.
Krusty, theres other areas of manuverability besides turn rate, though I will admit 'vastly' may have been overstating the case. The G6 just feels sluggish when you're going up into a loop for some reason, as well as when you start to get slower (as is the natural tendency in a fight). The G6 also feels sluggish in climb (I know this is largely a precieved deficency, but perception can effect the results) and acceleration. So yes, while the G-6 may not be much worse under ideal conditions, the G2 still displays better manuverability and handling (handling is a big reason why spitfires are so easy to fly. They don't have any nasty tendencies if you're just a bit too rough with the stick).
You're not sitting on autopilot with a spitfire either. Spit can do some nice climbing tricks, but they still usually get beaten out by a skilled K4 stick. And the K4's engine allows you to very quickly generate engergy, which is a very usefull trait under any circumstances. That energy (be it in the form of speed or altitude) can be converted into either a possitional advantage over an opponent, or bled off in the form of combat manuvering. The undesirable effects on low speed handling (easily avoided or compensated for if you know whats coming, as is true with all planes) is well worth the benefits you get in combat.
By the way, the G-14 barely outclimbs the 109K between about 4000' and 7500', and never gains an edge after. For example, at 25,000', the G14 is hanging around 2000ft/min, while the K4 is still at 3000ft/min. So you would be taking a very minimal increase at an altitude band of less than 4000', for markedly inferior preformance at higher altitude.
