If you sign up for the subscription before October 1, then you get TRS22 Platinum Edition that will continue to work after you cancel your subscription. TRS22 PE only includes Surveyor 2.0 at the moment and can be used with 5m and 10m baseboards. HD terrain is an Trainz Plus only feature at the moment. Of course, That might change in the future but is how it is now. If you build a route in Trainz Plus using HD terrain, You will be able to open the route in TRS22 PE but not edit the terrain or textures in Surveyor 2.0 in TRS22 PE. Basically, you can make sessions for it but any changes to the route will convert it to a 5m route when you save it.