It is important to understand that the Hughes Northstar 38 began life as an early IOR rule beater. This brought a whole range of seakeeping, rig proportion and motion attributes that in my opinion made them far from ideal offshore or short-handed cruisers. These were particularly good boats for their time, but this was a time when the racing rule produced boats that were not very well rounded and were not good offshore boats.
In a general sense, Hughes build quality was very good. (I owned a 1973 Hughes Northstar 500 QT.) Hughes was known for the quality of their glass work (Hughes built the hulls and decks for the nearly identical Hinckley 38 from that era), but designed as a race boat, these boats did not have the engineering safety margins that you would expect in a purpose built offshore cruiser.
Another issue with these boats was carrying capacity. Early IOR boats, had notoriously small capacity to tolerate excess weight before performance and seaworthiness was compromised. Increasing tankage or rigging size would be a big mistake if you planned to go offshore with these boats.
The fact that Fatty was able to heavily modify his boat attests to his luck and his skill as a boat rebuilder and a sailor, and not to the inherent quality of this design.