I fully understand what you are saying cherry blossom and agree that the Bf 109 was generally in the 350 mph and under IAS category, with the very high reported speeds being the difference between IAS and TAS. However, at speeds above 310 - 320 mph or so IAS, the Bf 109 was pretty much becomming a tough plane to fly. The good 109 pilot would attempt to get his opponent to fight at 180 - 290 mph, right in the realm of the best 109 flying characteristics. Best combat speed was right in the mid 200 range, with 250 mph being the point where NOBODY wanted to fight a Bf 109.
Coincidentally, these are the exact speeds where the majority of early Soviet planes operated, and they were fighting the Bf 109 at its own game. History will show how successful the Luftwaffe was at that. Once the Soviets and the rest of the Allies started operating faster fighters, the heyday of the Bf 109 was over and the attrition began. To be sure, the Bf 109 was adangerous opponent to the end. While not at the top of the game anymore, the better pilots were very familiar with it and could give an excellent account of themselves anytime if not overrun by sheer numbers, which they frequently were. At the end, they were short of pilots, fuel, and propellers, and simply could not field many fighters against the many-plane sweeps the Allies were flying.
I know there are people who claim the Germans were not short of fuel, pilot, or props, but they are wrong. Germany had the fuel but, if you can't get it to the airfelds where the planes are, of what use is it in a tank? Germany had many pilots near the end buy most were very green and had almost no combat experience much less time in the aircraft. They might also have had the props but, again, it they don't reside on the end of the DB driveshaft on a Bf 109, they are useless as wall decorations.
I am not a 109-basher, but it was what it was. As for its standing in history, I am one of the guys who thinks the Bf 109 ranks near or at the top of the chain for actual combat accomplishments, even though the war was lost from the German side. It ALMOST took the world and DID take the world's air forces into their worst nightmare. I KNOW the Fw 190 has its fans, but the achievements of the Bf 109 make it the top German fighter in my book, despite the fact that it SHOULD have been replaced in 1942 or 1943 and DID have glaring deficiencies that could easily have been corrected but never were.
Truly a plane that was more than it's paper performance ever suggested it would be and its debut gave NO hint of the achievements to come.