I've always wondered what the weight differences were in Cap, Merino, and Regulator. It takes some browsing on patagonia's site, but I found this:
Cap 1, 3.7oz
Cap 2, 4.0oz
Cap 3, 4.8oz
Cap 4, 5.3oz
Merino 1, 3.2
Regulator Insulation-lofted hollow-core fibers
R1, Polartec Powerdry, high/low grid, 6.8oz, jacket 13.3oz
R2, Polartec ThermoPro, mid-wt,fur-like, 6.1oz, jacket 13.1oz
R3, Polartec ThermoPro, high pile, fur-like, 7.4oz, jacket 16.7oz
R4, Polartec Windbloc, stretchy light weight (with membrane), 13oz, jacket 22.2oz
Don't know the relative thermo properties. R1 is almost twice the weight of Cap1. And, R1 is denser than R2.
I'd be interested in Richard's consideration of the Cap4 hoody as a replacement for the R1 hoody in his layering protocol.