As for many vegetation libraries on the market, there is integration within the plug-in available - the Xfrog Catalog add-on
In case of Xfrog models the folder structure is "more complicated" and you need to configure texture path by yourself, as mentioned on our web site:"XFrog Catalog does not configure the texture paths, this is responsibility of the user. Usually the texture paths must be added to the Max configuration, using Customize->Configure User Paths->External Files, but XFrog uses a texture folder for each model, so the number of paths may be very high, when using multiple libraries.
In this case we suggest to copy all textures in an unique folder, adding the folder to User Paths. To help you with this process, we have written a Max script that collects all textures with a single click. You can download the script from here.
Unzip the .ms file and launch it from MAXScript->Run Script. Select the source and destination folders, and click Collect to copy the files. When finished, add the destination path to the Max's configuration (User Paths)."
We understand, that in combination with the XFrog Texture Maps Collector
the installation process is quite complex, but unfortunately as this libraries are done by third party company (Xfrog Inc.) we can't modify it's folder structure. Thanks for your comprehension. Please feel free to check our Forest Pack support for XFrog plants
page, where you can find some more information like about the Material Optimizer
Generally, it's very hard to say which models suits best to your scenes. As posted here
:"Each library has its own pros and cons. HQ Plants include native materials for VRay and Mental Ray and doesn't use opacity maps (renders may be slightly faster). XFrog catalog is much more larger and includes species that are not available in other libraries.
In any case, both includes free samples, so users may evaluate them and see what fits better to their needs."
The same applies for Laubwerk / Evermotion / MaxTree models. As there are free samples available, probably the best way is to do some tests with them and than decide.