Intel wants to push the 440ZX chipset, but most of the Taiwanese motherboard manufacturers prefer 440LX. They have a good reason, because the LX-chipset is cheaper and a full blown PII-chipset, with support of five PCI bus masters, 4 DIMM slots and ECC. ZX is the stripped-down version of 440BX and thus not offering the same features as LX. The advantage of BX over LX is mainly the 100 MHz FSB-support, which isn't used in 'ZX-66' anyway. VIA's Apollo Pro Plus chipset is a new version of Apollo Pro for Slot1-systems. It is also fully equipped as Intel's LX, but even offering 100 MHz FSB-clock. This won't help much though if the new Celeron's are all overclock-protected.
The BX-chipset on Slot1 has got a slight edge over the Socket370 boards, but this could be due to the board architecture. After all the Slot1 test board is the Asus P2B, known as a particularly good performer. ZX and LX don't show any difference in Winstone 99, but ZX seems to have a better AGP-implementation, making it somewhat faster in Quake2. VIA's Apollo Pro Plus is definitely slower than the Intel chipsets, but that's what we already expected remembering the results of the Apollo Pro on Slot1.