Charles Talleyrand wrote:

I've read three things. The p51 is unstable in pitch with full tanks and the
resulting aft CG, and that a p51 has a high speed stall that's tougher than
most other WWII fighters. And finally the p51 has a higher stall speed
than other contemporary fighters.

The balance problem is caused by the aft fuselage tank. Many Mustangs have had
this removed. In any case, you won't need to fill it unless you're planning a
1600 mile trip. Stall speed in military configuration was about 95, which isn't
out of line with other fighters of the era and is actually a bit lower than the
Bf-109. I've read, however, that the plane doesn't give warning before the stall
and drops the left wing dramatically when it does. Len Deighton claims that few
military pilots three-pointed the Mustang because that gets you too close to the
stall speed. Some years back, I got to watch 52 of these planes land at Sun'n
Fun. Every landing was a wheel landing with the tail slightly low.

George Patterson
If you're not part of the solution, you can make a lot of money prolonging
the problem.