Honestly, as an owner of more smart trainers than a sane person should have, I’d not buy any of the current models available. I like my Kickr17, H2, Neo 2 and Magnus. I have an aversion to any Elite trainers and would not touch a mid to low level train from Tacx.
Per the most common recommendation, I’d suggest keeping the Road Machine (I still have mine as a backup and my fitting training) and add a power meter. If you have only one or two bikes to add a PM to, that seems like a better option at the time. ERG is nice, but not a necessity and not enough of an advantage to make any real difference in training effect.
I’d personally wait for the next gen trainers, and specifically about 3-6 months after they are released to see how the real life function and early reliability shows itself. There is a need for these companies to fix the common issues present in each one before I could honestly tell a friend that it is worth the money vs a power meter.