Hi Hans,
talking about the conversation of Grand Rapids, I have to say, it was me who choose to convert these textures of the great FSX Scenery done by Dillon Rocque into DXT3.
While it is possible for some textures to reduce them even further into DXT1, you have to check every single texture to avoid the results you discovered. I must admit that I was too lazy for that (except for the fence textures - but that is another chapter).
I think, DXT3 ist a great compromise between 32bit and DXT1 that offers the best quality in relation to the quantity for a satisfied FS9 user. The other people may have their joy with FSX and CTD's and OOM's or whatever they like - with their simulators.
Great to read that you also have come to this conclusion! Learning by doing! as they say. I have walked the same way as you.
So, keep it FS9
Dedl
P.S. And what the heck about long loading times. I know friends from the FS2004-Team who have more than 1500 sceneries active in their scenery.cfg. To fire up FS2004 gives you just enough time to get another Amstel-beer ;-) and enjoy your life... cheers!