Looking to get a 16 core, may wait and see if the X3D version gets a release date and the price is not insane, as I figure it will be 2 years until Z5 or ML anyway so the cost isn't that bad over 24+ months.
I'm most unsure about the motherboard situation, as I would really like PCIE5 for the graphics slot, and PCIE5 for 2 NVME slots as well. This might seem like total overkill, but I figure that's much preferable to the (IMO) stupid setups with more than 1 lower specced graphics slots or more than 2 lower specced NVME slots that I'm not gonna use anyway. We'll see if anyone will release such motherboards.
As for DDR5, I frankly have no idea how to play that game. Prices have been going down, and I'm not at all sure its worth gambling on buying now, considering who even knows if you'll get the rest of the parts on release date (many people waited far into 2021 to get their Z3 CPU's).