I'm running my Radeon LE flashed to Radeon 32 DDR on an Epox 8KTA3 (KT133A) motherboard with AGP 4x enabled in the BIOS.. I haven't compared performance with AGP 2x though in anything..
I have played a fair amount of 3D games, all run well, except for NFS4 (at 1024x768x32 it runs slow).