new GPU for AI tools: AMD or Nvidia?

Actually, at this moment I would wait a tiny bit before jumping if you are not bound to x86.

Yes?
Betazoid wants to upgrade an existing system (midi tower) within a certain budget.
RTX Spark systems will certainly not fit into the budget.
Desktop systems are unavailable at the moment.
All the announced notebooks fall into the ultra-slim category. They are usually not good replacements for towers.

And linux support is just not there yes. I’m sure it will be great after some time, but not at the start. Distributions need time.