i love the guts covers. I have ran the complete seats and the quality of their base is as good as OEM. I can't speak to different firmness of foams though, the only 'other' foam I have ran is the phantom light weight foam which is quite pricey, but definitely light weight and does not absorb and hold water like a stock seat can... the phantom foam is a little more firm than stock on the few bikes I've ran it.