It is best to replace it. Canopy is thick and will heavily distort a view of anything that you might have done inside the cockpit. This is often a problem with just Spitfire models because of the complex canopy shape. I bought a 3rd party vacuformed canopy from Aeroclub. It matches the kit very well.
Wheel wells are adequately deep with no details.
Undercarriage legs are molded together with the wheels covers - a serious drawback if you care about detail. Decals are thin with accurate color shades, but many Airfix decals have register problems, so check your model before you buy it. Before starting the construction, I checked the kit with the Spitfire drawings published in Aircraft Archive , and a couple of photographs. Fuselage shape is good. The problem with most of the Spitfire kits is cowling shape, and the Airfix model seems to capture the outline accurately.