I prefer frames that have the separate adjustable silicone nose pads rather than the ones that have the nose-piece molded into the frame. I find them more comfortable and I have had no problem with them slipping when adjusted properly. The silicone pads seem to hold on the skin without sliding. Temples are spring loaded, but I don't have them very tight as I get headaches if they press too hard on the area behind the ear. The helmet straps also tend to also keep the glasses in place.
As a thought - have you tried wearing a sweat band?