I've been flying MSFS since the 80s and have never been able to perceive a difference a special mesh file makes in the flying experience. I'm currently using FSX-SE (Win10, Geforce1080) and have been flying routes in the Andes and Madagascar and airports are either sunken deep into a hillside or atop a plateau several hundred feet about the surrounding terrain.  The same for rivers and lakes.  I've installed numerous scenery files claiming to flatten and render realistic the anomalies.  I've used ADE to solve some problems but others defy the well intention efforts of scenery designers.  I love VFR flying, especially in mountainous areas, and it seems that both FSX and designers are unable to render terrain more forgiving .... trying to land in a chasm 2k feet deep is challenging but not the kind I prefer (poor visibility, rain, snow, gusty winds make FS enjoyable).

What can I expect from a mesh file in terms of airports?  I run mesh complexity at 100 and resolution at 1m ... are there any other tweaks that will resolve the matter?

i never really see plateau problems or airport problems but i think it's because i use orbx vector which has adjustments for many of these things. i'm not really sure exactly. a lot of the orbx airport sceneries require 5m resolution so that's what i use (this is still more resolution than a lot of the data, which is 10-20m source at most, at least with some packages.)

i'm using the freemesh package which i believe also gets some fixes and flattens to the terrain to work correctly at problem spots. honestly not really sure, these days it's just not something i have to think about, the airports that are messed up for me are very rare these days. like there was one in mexico but it was a bug, the elevation should have been 2000 yet the afcad had it at 0, stuff like that.

for me the improvements are most noticeable in areas where the fsx default mesh is just super low resolution like in asia, south america...  a really high-res one can make a subtle difference in the usa also, some of the plains states get a very subtle undulation that isn't there in the default scenery or freemesh.. but the effect is subtle enough that i just use freemesh on my current install..

i know that some mesh packages like the pilots one and fsgenesis included files that also could modify the airport elevations to correct them.. the solution you require may depend on which package you use. 

 anyway i'm not sure if i answered your question exactly lol. happy flying!

cheers,-andy crosby

 

IMHO a high resolution mesh makes the difference between a small pimple on the terrain and a proper hill. To give an example based on where I live in the UK. there are 3 terrain landmarks within a couple of miles of each other. Stock FSX:SE had these rendered as bumps. Freemesh X improved greatly on that; I could now actually recognise where I was flying! VFR Real photo scenery took it about as far as one can go with their detailed 9.6m mesh - the hills are fully recognisable.