Danish,
in most cases, the baseband provides the best voice quality results, but it requires some efforts on the frequency planning.
if your cells are all the same height, and evenly distributed, the synth. hopping can give identical results as well, but with much less effort on the frequency planning.
if the network is multilayer, or irregular, it is almost impossible to achieve a good performances with synth. hopping. However, it is very simple to plan, and easy to maintain…
Regards,