Of course, using the P-51's advantage just gets you labeled a "pick and run dweeb" 
Don't get me wrong, I am not even that big a fan of the P-51, I prefer Luftwaffe birds myself when it comes to fighters, it's just always comical to me to see all these armchair heroes get so absurdly derisive in their thinly veiled tantrums over being outrun by a Mustang.
It'd be as absurd as telling K4 pilots that using their 30mm is lame.
The stereotype from the 51 is because it gets used as a Pick and Run bird 99% of its sorties, typically coming in at 15k over a fight and when any advantage is lost or even a CO-alt merge it runs. Sure 1% of the pilots can actually dog fight in the 51, however how many sorties do you have to fly to find even one pilot willing to dog fight?
Prime example of this was yesterday, was flying around in a Yak-9 and had engaged 4 different P51s, each time when any advantage was lost, shoot to the deck and run, even when I am vastly out numbered - which is great that people are so easily willing to run since it broke it down from 1vs4 to 1vs3, another 51 made a mistake and I took his wing off, other two 51s decided to disengage only because a few friendlies showed up.
It only gets it stereotype because of the massive amount of sorties flown from it, if other birds were flown the same way it would get noticed far more often. You don't typically see a Spit8 or Spit16 pick or run from every fight, usually its looking for a fight - even if its a Trainer at least its trying to dogfight.
