You can upgrade your current decoder and it will work, I just upgraded my tracks decoder two weeks ago because the new transponders that came in wouldn't work.

I do understand however that some decoders aren't upgradable and that's unfortunate but it's to be expected, it's a business and AMB has to protect their product.

Years ago when the MRT transponders came out I avoided them all together for this very reason. Did people really think AMB was going to stand around and not do something to stop cloned transponders from working?