I guess I'm the first the try out the new trees.
I did pics in the UK over my favorite default textures, and also in the Vancouver+ scenery area.
This tree package might be one of my favorite add ons yet. For one thing the trees look awesome, and it also upgrades nearly the entire sim. If there is a performance hit using the 1024 trees over the default 512 size I didn't notice it. I was in the 30's over the UK scenery, which is using extremely dense autogen. I have to use lower settings in the Vacouver+ mountains. I'm even using 8xS supersampling at 1600x1200 and 32bit textures on the Spitfire, and the 1024x1024 trees seemed to do fine.
Some of these trees have a bit of a scrawny appearance when compared to the defaults since they are more detailed and modeled differently, which can make the autogen look less full, but using the 512 resolution might help a little with that.
Overall this package seems to be a keeper and if you are drawn to the art style it might even be a must have. I'm certainly glad I decided to shell out the cash for it, as its that good. It steps up the whole sim. Now the whole of FSX has trees the caliber of FTX, though not rescaled and of higher resolution.