The IIvi dropped out of the news a while back, with rumors flying that it would only be sold outside of the US, and that proves to be true. The only real difference between the IIvi and IIvx is that the IIvi uses a 16 MHz 68030 chip in comparison to the IIvx's 32 MHz chip. I presume the speed hit is proportional. It appears that Apple didn't want the IIvi cutting into the Performa 600's niche, not surprisingly, but the extra machine does confuse matters slightly. But wait, now that I scan back through the TidBITS archive, we've never seriously talked about the IIvx. So what should you know about this machine anyway?
In addition to the 32 MHz 68030, the IIvx includes a 32 MHz 68882 math coprocessor and 32K of cache. It has 4 MB soldered on and can take up to 16 MB SIMMs in its four SIMM slots for a total of 68 MB of RAM. 8-bit internal video comes standard, and you can add more VRAM to support 16-bit color on the internal video, although 24-bit video requires a video card in one of the three NuBus slots. Other methods of expansion include an accelerator slot and room for three internal storage devices, which actually means one SuperDrive, one 3.5" hard disk, and another device, such as the AppleCD 300i double-speed CD drive. Alternately, you could probably use an internal SyQuest as your third storage device. The metal case and roomy interior give the IIvx a boxy look, but it's sturdy and cheap to manufacture that way, if a tad heavy at 25 pounds or so.
The IIvx probably performs comparably to the IIci but offers some additional niceties like the internal CD-ROM drive port. I doubt that the IIci will disappear immediately, but it wouldn't surprise me if Apple started to phase it out of production and dropped it at the next product introduction in the spring or summer, especially if that introduction resulted in a cheaper 68040 machine joining the price lists. Although a slick, classy machine with proven performance, the IIci is the oldest Mac in the current lineup, and I believe it's the only one that does not include a microphone. In addition, Apple may wish to get rid of that particular case, much as it wanted to get away from the old SE and SE/30 case.