I'm running the Kevlar ones too. I just think that the Hope OE ones are fantastic if you spend some time bedding them in. Don't get me wrong, the Superstar ones seem fine, they just don't bite as hard as OE. However, a front and rear set from Superstar cost less than one pair of genuine Hopes so I'll keep using them.
My Hayes are a different story; I'll only use Hayes sintered pads because they are immense. No other brand of pad works Hartwell in Hayes brakes. I tried some Goodridge ones in my old Mags and they were dire.