I'm sort of skeptical of how important EISA was from a market perspective. It seems to have been primarily a premium option-- you might see it in the super-exp

I'm sort of skeptical of how important EISA was from a market perspective. It seems to have been primarily a premium option-- you might see it in the super-expensive early 486DX workstations with SCSI and a fancy video card, but the commodity desktop with a 386SX, 4M RAM, and a small IDE hard drive was just using vanilla ISA. From that perspective, all the clone makers really did was being intelligently lazy. They just built IBM 5170s with faster CPUs for years. It was probably MORE effort to develop a custom bus and break all the existing expansion options. You saw some brief experimentation with that for the early "local bus" machines before the advent of VL-Bus, but that was quite a few years after the debut of MCA and ISA had legitimately run out of gas. EISA might have been important from the perspective of building a vendor-neutral standards process.