What were the main disadvantages of the Spitfire during World War II, and why did some pilots choose to fly other aircraft?

It looked like the ultimate fighter plane. The Spitfire became Britain’s most effective airborne fighter during World War II when engaged in duels at high speed. However upon closer inspection there were some major flaws with the design. 

First it couldn’t fly far. Its tanks weren’t big enough to carry much fuel. It meant that it couldn’t handle away missions in hostile territory. Planes like the Mustang were needed in their place—their range was much greater.

Its guns? Not great at first. The initial versions of the Spitfire had guns that struggled to shoot down heavily armed opponents. Larger guns were later installed but they'd a tendency to become stuck when needed most. Not what you’d choose for a battle.

Go too low and the engine could shut down. Slam on the brakes when pursuing your enemy and you’ve just put your aircraft in serious trouble. Troucing means trouble when each second matters to you.

But if you encountered fire from the ground? A Spitfire wasn’t built to withstand much damage. One hit to either the engine or cooling system and that was the end of your plane.

It gained its reputation for a reason. But when your job required a plane with real punch or an edge you needed something tougher. That meant very little chance of success for you.