I've not got it installed (1 minute!). I have successfully created groups and can activate/deactivate them. For instance, I have a group for each of the ORBX areas. Since I'm not flying S California when I'm in the RTMM area, I have that deactivated. So I have been able to deactivate SCA, CRM, NRM, NCA and my Hawaii files. When I check the P3D V4 scenery library, they are all unchecked as they should be. One click and I can turn them on/off, whole groups.
With what I don't need turned off, I thought P3D V4 would load a lot quicker ... but that's not happening. I'm bringing in all of the RTMM scenery and I'm sure that's what keeps it slow.
But I'm very impressed with the ease of turning on/off whole areas. But have to admit, so far, I don't see much difference whether they are turned on or off.
I'm only scratching the surface with what can be done with this (baby steps). I'm going to look next at the backup and restore features. So far, I've not used the xml features, only bgl.