It's actually GTE
And news of this switch has been LONG out there, so this truly shows OP's dedication to this motorsport
The Z4 chassis IMO can take it to the Vettes and Ferraris. It is lighter by 86 pounds, is 5.1" lower to the ground in overall height, shorter length wise by ~1 foot and a bit wider.
It is going to be a nimble car.
If you don't like the change because they went away with the M3 then you're not a true fan.
PS - The Z4 stock chassis has always had a stiffer torsional rigidity than a stock M3.
Long live the M3, but I can't wait to see this beast run. Really disappointed they canceled Mid-Ohio. I got awesome shots:
Mid-Ohio E92 M3
, on Flickr