I have a gel saddle and it has a cutout. It is Flite "Gel MAX"? or something like that and is modelled on the original Flite Titanium that I bought 15 years ago. It may have gell in it but the layer is so thin that it just gives a bit of Cushioning. The other saddle that feels exactly the same is a San Marco "Aero". Cut out again but the cushioning is foam. The compression on both these saddles is about 6mm but they both have the cutout. That cutout is the important bit as I still prefer a firm saddle. The important part for me is getting the sitbones in the right place and not sitting on the underparts.

And if you want to find out how uncomfortable a saddle is- Have a radical prostatectomy and try and sit on a saddle within 2 months- Then you will have to find the right saddle.