You know, it always bugs me when a guy flies his fighter as its designer intended and gets flamed for it.
Since the drag model was revised, the P-51s took a big hit in flaps out turning. I've tested both types extensively both online and offline. Therefore, let me share a few facts as pertains to the current Mustangs and their ability to maneuver at low speed and some advice for new pilots (and some vets as well).
1) Stall fighting... don't do it in a P-51. Even if it's against a poor turning fighter, it will leave you vulnerable in a plane that's big on speed, but small on acceleration. If your SA is such that you feel secure, fine. However, if enemy fighters are within icon range, you're asking for trouble.
2) Using more than 2 notches of flaps is pointless. Beyond 2 notches, its turn radius barely decreases, but the turn rate drops significantly. The more flaps you drop, the lower the the turn rate, and for dang little in reduced radius.
3) If you intend to reverse, before you merge, drop the first notch of flaps. This will significantly tighten the reverse right from the get-go.
4) Don't immediately reverse when merging with slower, better turning fighters. Extend a bit (about 2k, not 1/2 sector), then reverse while converting your E to altitude.
5) Learn when it's time to bug out. A good P-51 driver will maneuver with the enemy until he sees that he cannot gain or even maintain angles. Clean up the plane, unload and get some lateral separation. Recognize when it's time to get gone.
Ignore channel 200 whines... Better yet, give them a reason to whine. Every time they whine, send 'em a salute. If they challenge you to go to the DA, send another salute. I did this to some huckleberry one evening and I'm pretty sure he pee'd his pants in rage. Besides, anyone feeling genuinely froggy can find me in the TA 3 to 5 nights a week.
P-51s are very capable, but that capability resides largely in their speed and high-speed handling. Do not surrender advantages, practice building good E management skills. Make the other guy fight against your strengths, while avoiding his. Basically, common sense flying with decent SA will result in good sorties. Nonetheless, don't live in dread of losing fights as you will learn more from defeats than from victories. Defeats teach you, but easy victories will only build over-confidence, and that will come back to haunt you later.
Finally, know what your plane's limits and capabilities are. Know what the enemy's plane can do and not do. This is critical to success, regardless of what you fly.
Here's an example: Last evening after an hour in the MA, I went to the TA. Later in the evening, baitbug logged in and we were able to duel for a while. I flew a Bf 109G-2, he an La-7. After the merge, the fight devolved into a low altitude turning contest. Flaps fully out, the G-2 is pretty capable. However, it does not turn right as well as left. On the other hand, I knew that the La-7 turns better right and not so well to the left. Therefore, I refused to get sucked into fighting against the La-7's strength, and stuck to what I knew would work. baitbug eventually reversed into a right turn, hoping I would follow. I wouldn't. His reverse gave me the advantage and the La-7 could not overcome that advantage. These are very evenly matched fighters, and to be successful, each pilot needs to fly to the strengths of their respective fighters.
My new friend baitbug is very, very good in the La-7. Against his La-7, on the deck, the best I could manage with a Spit14 was a draw, and that only lasted until I ran out of WEP (the Spit14 has a faster turn rate, offset by the La-7's tighter turn radius). In contrast, the G-2 is somewhat easier to fly at the limit than the La-7 is.
So, understand that knowledge can be a weapon, providing you an advantage over a less prepared enemy (BTW, baitbug was very well prepared, and we discussed why I would not try to follow when he reversed his turn, we both were trying to get the other guy to fight against each other's strengths).
My regards,
Widewing