You’re correct about speed, I should have said climb rate. I was trying to be concise. My impression is that pilots preferred the P-51 for air combat, but the P-47 could take more punishment, which comes in handy near the ground. The A-10 borrowed the nickname Thunderbolt from the P-47 in celebration of its fantastic ground support role.
This should be "research-able" since there were quite a few US fighter groups in the ETO that converted from P-47's to P-51's -- hence there should be more than a few pilots who flew both types in aerial combat. Francis Gabreski got most of his kills in the Jug, and he was the top scorer in the ETO with 28.
Interestingly, Gabreski also flew Spitfire Mk IX's with an RAF Polish Squadron though he recorded no kills in a brief tour in that type.