As to the plane actually being discussed here, the P-51D, I've never understood why the P-51B is not an acceptable substitute. It is extremely similar to the P-51D. Closer than any two A6Ms, Bf109s, Fw190s, Spitfires or Yaks are to each other.
Not enough guns, not enough ords. If I'm flying a P-51 it's usually because I want a good ord package plus the ability to fight well after dropping it. And my gunnery just isn't good enough for 4 .50s, they're especially terrible to try and kill any bomber with, you pretty much have to park on their butt and spray them forever. Six .50s is already kinda marginal. OTOH a Spit VIII doesn't really carry enough ords to be very useful as a jabo so flying a Spit IX instead isn't much of a loss even though the difference in engine power is a bit more than that between the two P-51s. The same goes for the various F4Us, the loss of 2,000 lbs. or so of ords is more significant than the performance differences so ENY takes the F4U completely off the table for some mission profiles even when you still have some F4U models available.
I don't log because ENY kicks in but I will log when it gets to a certain point, depending on the situation. As has been pointed out once it gets past about 20 jabo choices become extremely limited and CV choices become atrocious. If it gets to the point where I'm forced to fly an A6M2 because that's all ENY will let me fly, forget it, I'm logging. I sometimes fly a 190A5 for the fun of it, and it works out okay in a furball where your SA and decision making is as important as your plane, but in a 1v1 against something that can build E literally twice as fast as you can it's hopeless, you'll never get a shot in unless the other player is completely incompetent (or more than usually chivalrous). And as many have mentioned ENY rarely reflects the actual numbers in the fight you're in. Which country is more heavily engaged on which front is more important, and ENY does nothing to reflect that. One country can be outnumbered substantially and have a high ENY because both other countries are ganging up on the one that can only fly early war planes. And as I said in the other ENY topic it gets really awful at night when a lot of people are logged on but not actually playing; in that situation it's easy to be outnumbered 2-1 and have a 25 ENY because you have tons of people who are AFK all night.
Side switching is not a useful option late at night. The numbers swing again and you're stuck on the side you've switched to. When you get down to 50 players or less in the arena ENY just doesn't work.
The idea of spending perk points to fly planes that would otherwise be unavailable due to ENY is interesting, but it suffers from the same two flaws as the existing perk system does: one, it would encourage timidity because people want to keep the perks (this could and should be fixed by using up the perk points regardless of whether you die, ditch, or land) and two, more important, it means the uber rides would be out of reach for newer players but easily available for long-time veterans, which is exactly the opposite of how things should be. New players are the ones who really need to have the most capable and easiest to fly planes to have a chance, and skilled veterans are the ones who can consistently get kills in Mossies and Brewsters.
Don't let the door......
With numbers as bad as they are and still dropping that attitude is not helpful. Back when there were 2000+ people playing losing a few people didn't matter, but we're dangerously close to a tipping point where the number of people leaving starts to snowball since the ones who are left can't find decent fights and quit the game themselves.
