So far I've just been continuing to use Handvoll (ARS) instead of Hand voll (NRS) precisely for this reason: it seems a lot easier.
And it's more like English. Separating it somehow sort of reminds me of 'Baa, baa black sheep ... three bags full,' which seems rather quaintly old-fashioned for 'bagfuls.'
But if Dragon says Hände voll, I may have to reconsider.
Any other votes? The German half, er, three-fourths of this forum needs more opinion polls. Selkie would probably share a bottle of her prospective virtual case of Merlot
if we could get, say, 10 people to vote for Handvoll ...