The spitfire is generally considered one of the ultimate world war II fighters due to it's role in the battle of britain and how easily an experienced pilot could outmaneuver german fighters. Operational range of 390 miles, speeds of 460mph, and an armament of 4 20mm hispano cannons. It was a deadly little fighter and many considered it superior to the hellcat as an interceptor, it's still an ongoing argument as well but specifications suggest that the supermarine spitfire was the superior fighter.
Planes like the bombers don't get as many kills or damage out as a fighter might so their experience and credit rewards are higher, in my hurricane I can easily fire it's rockets across a column of armored cars for 5-6 ground kills before pulling up into an air to air for a few air kills, by the time a bomber has reached the ground targets and lining a bomb sight I've already wrecked a column, generally, bombers are the planes that crack pillboxes because only 250lb bombs can really damage them. Then they kind of hover around until they see another ground target, bomb the airfield a little, or wait for someone to shoot them down.
Personally, I prefer using a beaufighter for attacking ground targets because it can just as easily destroy fighters as it can destroy ground.
One such example of the beaufighter, spitfire and hurricane as fighters :3
Note though, my experience is tied entirely into Britain's tech tree, put me in an american fighter/ground attack and I would suck until I got used to their capabilities >: