supl.vodafone.com also worked via wifi, ISP = telenet.be

Learned some things, though: clearing the location stored in system.nokia.location does not clear the caching, only a reboot helped.

To test, I've hacked one of the old update scripts to only use ACWP and only print results, not try to update latitude or whatever... - script attached.

so, in short:
supl.google.com + wifi or 2G: mode 1 location, center of country
supl.vodafone.com + wifi or 2G: mode 2 location, accuracy 188m