1. Five brand new routes with sessions, locos etc (probably the best quality routes of any version)
2. Loads of new content for building routes
3. Multiplayer Surveyor (Build and drive online with friends)
4. Unified Driver Surveyor (switch instantly back and forth between editing and driving)*
5. New camera options (Drone, Walk etc)*
6. Backwards compatibility with all your existing content and DLC
7. Supporting N3V Games so that we can continue making Trainz better year after year.
* These were also added as part of TRS19 Platinum Edition.
Trainz Plus membership would give you Surveyor 2.0 plus new features and content regularly added, and you'd get a $2 a month discount for your Lifetime FCT, so 13.5 cents a day if paid annually.
Gold Class would add all the DLC on top of that, Preview Pass to check out the latest DLC before it's released and a store discount.