Excellent. WWII aviation is my specialty...
Note some things first: I don't like the P-51. It's a plane with a bloated ego/reputation. It deserves a lot of credit, but probably not in the magnitude it gets to date.
The P-47 was a great aeroplane. But, just like the Mustang, was more suited to some roles than others. At certain high altitudes, the P-47 would outrun the Mustang with little problem due to the massive turbo-supercharger that filled in a lot of the fuselage. The exhaust from the thing made it almost like a turboprop because of residual thrust being vented. Keep in mind the P-47 was the heaviest operational single-seat fighter of the war. Being over 20,000lbs gave the plane a massive wing loading. If it was going to maneuver, it was going to do it at speed. Even in the thin air at high altitude, a "Jug" at speed was a dangerous foe. Because the fuselage was so densly packed with the mechanisms of the plane, as well as the redundancy/reliability of the radial engine, the P-47 was immensely survivable. It had a great deal of power, meaning it (despite its weight) could lift a great deal of ordnance. So, it could perform either role, escort or attack. In my opinion, it was a better attack platform.
It would have been great if it would have stayed that way for thee rest of the war. Here's why (most likely) it got replaced by the P-51: (a.) economy. The P-47 used huge amounts of fuel. The engine was thirst, and the airplane was BIG. Thus, you've got a large aircraft which has a big, blunt frontal area. Drag. (b.) logistics. Good things get replaced if there's not a lot of them. An example is already in the thread: the F-14. Now, the P-47 did see service until the end of the war, but in limited numbers. Primarily this was the P-47M in Europe and the N in the Pacific. The M and N were basically the same, but the N had longer wings with fuel tanks therein. Both had uprated engines (2,800 hp I think?).
Like all aircraft, the P-47 and '51 were good in their respective roles (even the early models), but that did not make them great at everything. The P-51 is a great example. Sure, it had a good payload in the ground-attack role, but it could not take a hit to the radiator. Which was located in the center of the plane, on the bottom of the plane. Which, made it hard to miss... Still, I will concede that the P-51 was better for the aerial superiority mission.
On maneuvering... I'll get to that later. This post is long as is...
-Thaeris