"what was that called? PCI with VESA extension, or something like that?"
It's an ISA slot with VESA extension. VLB, or VESA Local Bus, could run at 33, 40 and 50MHz bus speeds, matching the CPU frequency. Combined with an AMD 386-40 or Intel 486DX-50 (not DX2) it easily outperformed EISA and MCA. PCI killed them all off, of course.