Which Saddle?

Ed made a cutout in his, so has tried both: pretty sure his answer will be "SMP".

I tried both but found the cutout didn't make much difference and just caused the saddle to sag uncomfortably. Went with the standard. I otherwise ride a Romin Evo

Soft saddle like the Cambium still cause compression in the wrong places, the softer the saddle, the worse the compression (when your bones stink into the saddle to hit the shell, the more the soft fabric come in contact with your undercarriage).

Ideally you should be either supported by the sitbones (traditional saddle) or the ischiopubic ramus (SMP saddles), a cut out should relieves pressure from the soft issues of your undercarriages.

I cut the Cambium and it's only slightly bigger than the actual one, (but with the same amount of flex), it helped, but still put too much pressures.

The SMP is the first saddle I've ever had that I can do a 600km audaxs ride and still not feel anything sore or even a tiny hint of pressure in my undercarriages, it just doesn't exist, so forgive me if I only wax lyrical about the SMP because it finally work for me*.

*(the nearest saddle that work for me was the Fizik Versus range with a similar continuous cut-out in the middle which prompt me to get the SMP after feeling the pressure after 40 miles when the soft fabric stink in and compressing the soft tissues, 35 more miles than other saddles).