Having both Domikey SA and SP SA here - SP are higher quality overall, for the keycaps themselves (better colors, better legend consistency, slightly heavier keycaps with slightly better construction).
SP packaging though is lacking (caps are thrown in plastic bags) whereas Domikey have really neat trays that keep each keycap in place properly, and a very nice box around these trays.
Overall Domikey SA is still good. SP are the best so far IMHO.