Everyone is also forgetting the massive disadvantage any Spit has against a 109 in that the engine cuts under negative G.
So if you catch a Spit of any mark on your tail, dive away as per RL. Or even negative G turns.
I got on the tail of two 109's last night and as soon as my bullets hit, the guy bunted away.
Inverting and diving is possible, but my reflexes aren't what they used to be.
I did follow him in manoevres, just, and got a few more rounds into him, but unfortunately his team-mate shot me first.
So even if the Spit II is faster, there are still ways to overcome.
Last night was the best online CoD experience I've had to date. Just fantastic.