One thing that always bothered me about DX9 was FSX's internal framerate limiter. Using the FSX internal limiter, once the desired framerate was reached the excess thread time was then turned over to the terrain loading, which helped with keeping the blurries at bay (always my bugbear with MSFS ever since FS2002!). The problem is there was always something wrong with the internal framerate limiter. For example, without the limiter I might be able to hit 40-50fps, but as soon as I put the limiter to 30fps my framerate would drop to 20fps. I nearly always had this problem across multiple systems.
With DX10 I don't see the same behaviour when the internal frame rate limiter is used.
I totally agree about the price. It was a mistake putting it at $30. The guy either got greedy or listened to some really bad advice. I remember prior to the release the hype for this was really getting out of hand on Avsim especially, and some were predicting it would only cost $10, would easily sell 250,000 copies and would reinvigorate FSX and cure all the old performance complaints. Given the availability of the free shader fixes that the same guy did, I really don't think the addition of a basic GUI and a few more fixes is worth the $30 I paid.
As for REX4.... I think it's a huge improvement over REXE. I always found the cloud and sky textures in REXE and its predecessors to be way over the top and looked out of place in the sim. With REX4 the textures look much more natural and fit into the sim much better. I also really like how loading a texture theme now takes a few seconds as opposed to minutes waiting with my screen doing all sorts of crazy stuff like it did with older versions.
