I have heard and seen many German pilots say that with the G-series, the Bf 109 was well past its prime. While it COULD be maneuverable at 180 to 280 mph with the slats out, if you stayed fast it wasn't all that maneuverable with the slats retracted and was reported to be downright vicious in the landing configuration. Can't say myself, but I've heard both high praise and some rather harsh criticism of the 109 from the guys who flew it.
That being said, the guys above who said to fight with your aircraft's strengths are correct. Correctly flown, the Bf 109G-series were dangerous opponents right through the end of the war, even if not quite a match for the late model Spitfires, Tempests, and P-51's being flown in large numbers relative to the Bf 109 flyable population. I'd say nobody took a Bf 109 for granted unless they had 100+ friends in the immediate vicinity and the Huns were a flight of 4 trying to stop the bomber stream. That happened and the Germans attacked the bombers with bravery if also with some futility.
One on one the Bf 109 had its strengths and weaknesses, just as did all other planes. The 109 had possibly more weaknesses than most, but its strong points were good ones. It was always a strong climber, was maneuverable at relatively low speeds, and the cannon could do some real damage with one hit. It was simple to maintain and tolerated harsh conditions quite well. On the minus side the range was terrible, the landing gear was flawed for the entire series, the canopy was the worst on any fighter of WWII, it had no rudder trim and the stick was very difficult to move when anywhere above 330 mph or so. At 400+ mph the stick was almost set in stone.
So, although the Bf 109K series could hit 450+ mph in level flight, they weren't fighting when they did so. They were running to or from a fight. The G-series was muich the same as regards the stiffening up of the controls at speed, and that is possibly the source of the comments you were reading. While true, there were ways to fight the plane around these weaknesses except for the range and abysmal canopy. The G-series had all the weaknesses of the K's and not quite the same speed, at least in level flight.
But they were also quite successful in shooting down Allied aircraft, so the balance sheet must have been better than even in retrospect. You cannot call the Bf 109 series of aircraft other than successful in their designed tasks. They shot down more enemy aircraft than any other fighter in history, so at least SOMETHING was pretty darned good about it.
Taken as a whiole, I'd say the Bf 109 is one of the immortals and deserves a place near the top of the heap, if only to reflect its combat record. Some in here are not fond of the combat record as a measure and that is fine. What other measure should be used to determine the best combat fighter? Certainly operational losses are one measure of reliability or lack thereof. There are others and they all have a place in peacetime..
To me, combat record is the ONLY measure that counts when talking about combat aircraft. It is, after all, the evidence of performance in the cricible of combat. The Bf 109 was one of the best of all times at that task.