Actually, I don't thinks VGS's compatability surpasses ePSXe's by that much any more. Think about it, many games that run on VGS wouldn't if not for those wonderful patches by people like Aldo, Whitehair, DecDave, etc. If it wasn't for those patches, Wild Arms 2, FF 9, and many others would not run at all w/VGS. But ePSXe runs those games fine right from the start. So I would say that ePSXe has actually surpassed VGS due to this fact and the fact that ePSXe is being actively worked on, and VGS hasn't seen an update in some time, even before Sony bought it. So, for my money, ePSXe is clearly the superior emulator here. VGS was great, but is now starting to fade (sx/amiga plays taps for VGS).
sincerely,
sx/amiga