I would like to have engine failures. Very realistic I would say.
One you can add as an option for realism.

But the basic for CoD must first be all right.

stuff like performance changing according to engine hours, wear and tear, random engine or magneto/pump failure should all be there. The idea of the percentage is just to find a balance in the alleged lack of accuracy. You wouldn't know what plane you have, whether it performs as it's supposed to or not, just like in real life, and this could iron out the "perfomance to chart" issues in a compromise form that might find everybody happy. We all would have the same fair chance of a failure or a particularly performing / not performing plane (within minimum percentage of course, which would be so marginal not to make it worth to restart or do any other silly choice).

I don't see why you guys immediately point at it as a whine/cheat factor. It's not the mentality that would help us develop further. Whiners can be politely asked to either take the rule or find another game (since we're aiming at accuracy here), while cheats can be solved by giving a limited number of planes available, which you have to take care of and manage like the real thing, instead of yanking it in the air like an air racer.

There is randomness and variation in the old game, 1946. Some can be mitigated by pilot, some can't. First, fuel load. This impacts performance at any point in time. Pilot has some control over this on how he flies. Pushing the throttle will use fuel at faster rate during the sortie and a G-10 at 100% fuel performs much different then at 30%. So, there are times you may turn with a spit and other times you won't. Second, DT put in the latest patches engine reliability randomness and g-limits that tweak the airframe if exceeded, both impacting performance. The engine reliability is only partially controllable by the pilot. Somewhere in the "read me" for that patch it says something about just having a bad day or reference to bad production as the war went on. So that element is not controllable. But if you are easy on the engine, it says your odds improve. The g-limit, however, is fully controllable by the pilot. Third, there is randomness in loadouts that impacts weight and performance. Sometime you choose the 108 cannon, sometimes you don't. That added weight should change how you fly it imo.

Bottom line of this jumble, I like the idea of variation as long as it is realistic and not redundant to what may already be built into the game. The short time I spent with CLoD, it seemed to me they had all these elements carry over from the 1946 game. Since I'm not playing it, I won't vote. I'll just say I think this should be low priority because I think it ultimately gets blurred by all the other randomness that may already be in there. I'm also not a believer that 5 kph in top speed makes a difference. If someone is beating you because of that, you need to do something different.

Your asking a lot from the developers and if you can't see the difference why even bother with it in the first place.

Regarding the whiners being asked to leave politely AHHAhGhrgghh.. Cough.. Splutter... Ah ah ahem... Take a look at some of the other threads which contain whiners that have no intention of giving MG a rest :(

Very very well said.

Wow! I didn't expect this :)

The idea I had behind this, was that people often complaned about very little performance differences between aircraft. Especially online. The reason is simple: If you have a plane which is, let's say 2km/h, faster then your ennemy, he won't run away because sooner or later you will catch him. And this happens quite often online because you don't have to worry about fuel, getting in a dangerous situation, leaving your wingman alone, damaging your engine etc. If everything fails: hit "refly".
That's why random performance (+ or - 3%) could bring a little more realism to the game because planes with little difference in perf. would be seen as equal. Like in RL. In the game, a very slight difference is considered an advantage because you know you have these 2km/h no matter what.
Btw. these 3% where considered to be acceptable in RL if I remember correctly.

Of course we need to have RL performance as a base for this calculation. So one step at a time, but I think it would help the game in the future and calm down the FM discussions over ridiculously slight differences.

I don't know if that's a lot, but anyways..

Whiners can suck my throttle, I think that once a software house decides on the way to proceed and justifies the choices, setting a benchmark and a position in the market (accurate sim vs not so accurate), then it's either their way or the out way.

Yes, it could smooth FM errors and lower the count of "inaccurate FM" whiners, but sadly it can increase amount of "quality control" moaners. You know, the ones that would say German planes should be 97-103% of factory specs, and Soviet ones should be 75%-95%, and so on. Someone would bring documents about plane testing before its acceptance to service, and how high quality control was, and in essence we would have same debates like we had over FM.

Yes and another things that I can now mention (at home, hate typing in this forum with my iphone) you have touched on. SOME would say/moan that due to the bombing the late war Luftwaffe aircraft would have a huge performance difference. Then the Luftwaffe could come back and say/moan that allied pilots should have a handicap due to lack of experience etc etc etc..... and while were at it the allied are allowed twice the number of pilots that the axis have as thats realistic :D okay I jest but all these things are true/realistic.

At the end of the day realism reaches a line and the developer has to determine if the game crosses that line and you start to loose fun or you try to keep the game fun.

Like others have touched on the -/+3% performance can be found when going up against pilots of varying skill.

EDIT:

I recall reading about various aircraft that, from different places of manufacture the performance changed, the spit I think was manufactured without following the blueprints correctly at one factory and the same was said for the 109 a certain factory was said to build a poor performance aircraft.

thats a 'maybe' from me. I, for myself, striving for maximum realism (actually, I'd buy a DCS: Bf-109E-3 or a DCS: Spitfire MkIa in an instant!), would love to have production tolerances simulated in a reasonably good way.
But, let's face it: That would mean thousands of threads like "WTF? Same plane outclimbing me! BUG!" for years to come...

As for engine failure probabilities: there's actually a slider for that in general loadout options, regulating engine/airframe 'age'. Though I presume it doesn't work, just like the rest of the loadout screen.