Based on the title of your thread you wanted to know who builds the best quality boat. Again I think equal power Fountain is faster, however I would hold the quality of the fit and finish of my Donzi up to any Fountain built. No expense spared from McLeod bolsters, McLeod electric foot wells, standard Gaffrig gages, color coded diamond plated engine compartment, on and on.
Donzi's build a very heavy performance boat that can handle most any condition. At 70 plus MPH the boat handles like you are going 50.