I changed the files bit more... I have increased night lighting textures to 80km as I find they don't affect CPU at all as these are just textures on the ground and it looks great from high up ;) Cities are now set at 20km, I think most people with decent CPU and video card will be able to handle this.
First screenshot over Krasnodar (20km distance set for buildings - density of Structures in Graphics.cfg is set to 80, fading in to full render at 4km) Ideally I would increase this bit more but then it hogs the CPU too much
Night time... I am about 18km off the coastline at 20000ft, you can see the night lights of towns/cities/villages to about 80km... to me it looks pretty good and doesn't affect CPU at all, if it affects anything it should be more textures loaded into graphics RAM (my card has 1GB of VRAM, I think from now on if you're buying new video card it should have 2-3GB of RAM as there's more and more high size textures in games)
attached new archive with all the files (just drag and drop into main DCS A-10C directory)
EDIT: I'll add my PC hardware also: Win7 64bit, i7 950 (o/c to 4GHz), 12GB DDR3, HD5870 (GPU o/c from def 850Mhz to 900Mhz) running 1920x1800 (exporting MFD's) in windowed mode, etc so pretty normal high-er end machine these days
EDIT2: just played Sierra Sunset mission and it was very playable, I did not get bad slow downs at all even if using TGP and Maverick at the same time.
EDIT3: uploaded new archive as I found I made mistake in districts lights value