I'm sorry, I actually got them mixed up. The Revolt X splits power between two motherboards, the Revolt Pro is the stackable PSU. I meant to ask about the Revolt Pro 1000W, although I'm guessing they're both essentially Seasonic Primes.
Apologies if this is already talked about (I have no idea how to search keywords on the forums), but is the Phanteks Revolt X 1200W any good? They're made in partnership with Seasonic and they're very interesting PSU since they can combine with other PSUs.
EDIT: The Revolt Pro is the PSU that can combine, not the Revolt X.