Put newbies in both Spit V and 109F and Spitfire will win every time.
Put experienced pilots in both and 109 will gain the initiative, while Spit will be on the defense throughout the fight.
For its time, 109F is a great plane. It gained performance and maneuverability over 109E.
One on one vs Spitfire, you should first outclimb it (from co-E start). After that you BnZ it at will. You only have to watch for Spit not to give you a HO shot. If you screw up, you can outdive the Spit and climb above it again. Your WEP cools down quite faster than his so you will win prolonged E fight no problem.
Against Spit IX you can even turn, but Spit still holds a slight advantage. You are marginally faster and better accelerator, while climb advantage is negligible. Careful here.
How's 109G-2, compared to 109F-4. I know I like 109G-6 pretty much, it adds some punch. It can E fight as successfully F-4 and G-2, but it is a better BnZ bird.
Another thing I noticed. If you watch climb curve for 109F-4, you see it peaks on the deck with something close to 4000 fpm. 109G-6 manages the same, but its peak is cca 4300 fpm at 5k. Interesting

.
zizouuu