Not much. You're stuck with shoddy VIA core logic either way. Kinda danged if you do, damned if you don't. 😛
8KHA utilizes the terrible KT266 chipset. Besides a host of deficiencies, the most notable is the inability to push the system's FSB above 138, without losing your USB ports. That is, assuming you can ever get them working in the first place. 🙂
8KHA+ is the same board, with the exception that the north bridge is 8366A (KT266A). It does "fix" the USB sh!tout @ 138 issue, but, unfortunately, causes other issues and fails to remedy a suite of issues which have existed in each and every chipset for the past several years.
I can't recommend either board.