The Yak-3's are beasts. Small, light, and a powerful engine. It's like a Mustang 5.0L engine strapped to a go-kart.  The only downside is that they lack ammo count. Usually only good for 3 kills. More if you're an ace shot.
If you're referring to the Spitfire, you must mean the clipped winged XVI or XIV - both should probably be perked  

...amazing rides  

  ... and their sheitfires...what do you expect?  A really good pilot chooses a Spit VIII for the MA (cough).  The XVI has great low-alt performance. 
Besides, who doesn't love to get themselves a few kills of Spheitfiurs? 
Anyways, isn't this the same MA before the early/mid/late war splits? No one really complained then... 
