It sounds slow to me - members should be fairly minimal data and I'd have expected that phase to have completed within 12 hours, unless you're running on some really crappy hardware.
@
Mike might be able to advise if he's around, else submit a support ticket.
ISTR that disabling/removing indexes helps - you rebuild them as a last step
after all the data has imported - maybe search here on XF.com for prior advice about that.
Cheers,
Shaun