Give me an example of what New Content you get early access to under the Silver sub?
The Silver Subscription no longer exists. It is now just two levels of subscription.
Trainz Plus, and
Gold Class (which includes the Trainz Plus subscription)
In the latest Newsletter:-
Trainz Plus and
Gold Class members get the following new DLC releases free:
Amtrak Superliners
BR HST Intercity 125
Tornado AI Steam Loco
... and coming soon ...
Datsun Junction Model Railroad
British Model Railway
Gold Class members get (in addition to the above) the following new releases free:-
Budd RDC-1
Blue Comet 2.0
plus free access to all DLC
I acquired the first payware DLC in 2010 and have had continuous use of it since - at zero annual cost.
But you paid for that so it is yours to keep. As a Trainz Plus or Gold Class member you can also buy any DLC item outright and it is also yours to keep (at zero annual cost) even if you drop your subscription. I have done this for a few items despite being able to get them free - e.g. to support Oleg. With the membership you can have it at no cost and if you decide you don't like or want it then you can delete it and you have not wasted the purchase price.
The main reason I don't have a subscription is because I don't fully understand what the offer is, and what will happen to my various projects if I decide to not continue.
Obviously, you will lose the ability to run the latest version of Trainz (as Trainz Plus). Currently that is TRS22 (disguised as Trainz Plus) and it will automatically become the next latest version (e.g. TRS25???) when that is released. So you will lose the ability to continue with any project with a build number greater than the one used by TRS19, your last purchased version.
In my case that will be TRS22. If, for some reason, I discontinue my subscription after, say TRS29 is released (if we all survive that long with the current mess in the world) then I intend to purchase outright the latest stand-alone version (e.g. TRS29) and continue on from there with purchases every 2-4 years, like I have always done since I first acquired Trainz.