I would rather have a PSA JAKL upper mated to the IRG original NS18 lower.
The problem with ACR is that once all the problematic features and short comings are stripped out, it is just a PAS JAKL in the eyes of the US consumers. They can't beat PSA JAKL in price point with PSA's massive scale of vertical integration. and the JAKL is probably a more simple and better design to start with.
My guess is that it will be an expensive gun with aluminum lower, and it will target the fanboys. I kinda see it as a bad business decision if they go ahead.