I bought the unbelievably cheap £1.69 one from ExpressPro, and was slightly slightly disappointed that it only had 4 external ports and no internal ports, rather than 4+1 or 5+1 as is shown in the item picture. However, that's really nitpicking when it costs so little. A PCI card is usually cheaper than a hub, and involves one less irritating external power supply.
The card I received had a VIA VT6202 chipset, and seems to be perfectly supported on OS X with no additional drivers, despite the fact that the 'Mac OS' option on the packaging was crossed out. I just plugged it in to my MDD G4, and everything worked, showing up in Apple System Profiler as expected.