The father of an older colleague of mine flew both Spitfires and Mustangs in WW2, flying out to Norway and dog fighting like blazes with the Luftwaffe squadrons stationed there. He told me that the Spitfire was so sensitive to fly the pilot could bank it by just leaning to one side. Newbies taking off in the Spits for the first few times would bunny hop through the air as they tried to keep level.
However he said the pilots much preferred the P-51 because they could trim it to fly hands off, something you couldn't do with the Spit. By the time you had flown out to Norway in a Spit you were physically knackered and not in the best condition to take on the crack German squadrons operating from there. Then of course you had to fly back, so because the P-51 was more civilised it was much preferred.