I bought it last night and think, for a beginning, TerraMaxx is okay. I say that because I am not satisfied with your vegetation assets for the most part but I also know that this can be easily updated as TerrMaxx heavily makes use of the XP library system - and that is really great, everything seems to be costomizable by scenery designers and making scenery compatible seems to be not too hard.
So... I'm digging deeper into it but I did not find the demo scenery package in the files. The manual mentions the SeasonsXP library and I did look at it already, but I still have some questions regarding seasonal overlay orthophotos and their propper implementation. Where do I find the demo scenery?