OK, I figured that because they are designed to be strong more than light, that they might be 'chunkier' on the spokes.

My 7x17" Pro Race 1's were ET35, but they had a good design for Caliper clearance. They cleared my Brembo's/330's by a mile.

My 7x16" Pro Race 2's were also ET35, they have a design that isn't much different to a 'normal' Alloy Wheel and I had to use a small spacer to clear the brakes. I also have to have the wheels balanced often as the calipers knock the balance weights off!!

Another idea, will Compomotive provide cross sectional working drawings of their wheels??