TRS22 SP2 introduces a number of new features and updates, and also introduces "Compatibility Mode" for the new HD terrain.
HD Compatability Mode
While it is possible to load routes containing one or more HD terrain baseboards in TRS22, the resolution of the terrain and texturing IS NOT HD. Both terrain and textures are displayed at a lower detail level approximating the 5m grid.
HD Compatibility Mode
Since TRS22 and Trainz Plus share trainzbuild 5.3 format, it is possible to load HD routes in TRS22. There are some important differences to note:

* When a HD route is loaded, the terrain and textures are displayed at a lower detail level approximating the 5m grid.
* Any fine details included in a HD route are "smoothed".
* HD routes cannot be edited in TRS22.
* HD routes can be converted to 5m or 10m grid, which will then make editing possible.
* Once saved, this process will remove all the HD detail permanently.
User Interface Updates
As part of the upcoming "Living Railroad" update, we've made a number of improvements and additions to the View Details and Edit Properties dialogs. The overall goal is to provide more information about all aspects of your railroad including trains, drivers, AI and industries.
Find out more detail here.
Water Effect Layers
A number of updates have been made to the Water Effect Layer.
You can now create multiple Water Effect Layers, each with their own assigned color.
Color is updated in the Advanced Options tab when editing a Water Effect Layer.
Find out more here.
Maximum Draw Distance raised to 22,000m
The maximum draw distance has been increased from 15km to 22km for the 5m and 10m terrain grid.
(HD terrain always displays out to 30km).
GPU Clutter
Moving the Clutter effects to the GPU means smoother rendering and potentially better performance. We're continuing to work on updating the capabilities of clutter which allow for lots of extra detail up close without siginifcantly impacting frame rates.