When you first start playing this game you want to dogfight, because that is the ultimate shooting experience, so you choose a spitfire.
Maybe the spit 8 as recommended in some of the trainers files. Then perhaps a trainer tells you the 16 is more competitive in the M/As.
You learn that you can get some kills but usually get killed by better pilots because your gunnery, acm and s/a suck.
Then you have to fly a spit 8 or 9 because of eny or a seafire off a carrier and you can get some kills but usually get killed by better pilots because your gunnery, acm and s/a suck.
The 16 is not a magic plane that turns a noob into the red baron, you would have to be a fairly decent pilot in the first place to be able to utilize it's advantages and would probably have the perkies to afford it, were it perked.
I started flying the the 8, 9 and seafire much more now because I find I do about as well and folks are less likely to think any kills I get should have an asterisk next to them.
As bad as I am, I have managed to kill a couple of 16's.