It'll be interesting when the Ki-84 gets introduced.  
As far as the La-7 goes, I think it is the best plane in the game right now.  I'd take one against a Tempest rather than fly the Tempest (performance is almost identical, La7 flat turns better but the Tiffie has a VERY slight edge in the vertical plane).  The only real weakness the La-7 has is the pilot.  Most La-7 pilots in the MA couldn't find their bellybutton with both hands and a candle, so even though their plane might do everything better than yours..  they don't know what to do.  Typically they'll overshoot and run, or if there are 2 of them they'll typically overshoot and die (then the last one left will run instead).  
As far as the 'best' unperked planes in the game go (for fighting, not Bore N Zoom)- although I don't even think the Spit and N1K make the list because they are gangbang victims for the most part.  I guess this is my list of best planes that are faster than all the Spits and N1K2s.  I also listed what I see as their primary weakness.
1.  La7 - Essentially no weaknesses.
2. Yak9U/ 109G-10 -  Low Firepower, no other weaknesses.
3.  P-51D-  Poor Acceleration, Mediocre Climb.  P-51Ds can flat turn a LOT better than people think they can, of all the planes listed above the P-51D out-turns them by a WIDE margin.
4.  Typhoon-  Poor Rollrate.
Thats really all I can think of.  For a list of 'fighters' the Dora doesn't even come close to making the list imo.  Crappy climbrate and turning kill it.  Has good firepower for a Bore N Zoom artist though.