I bought a used Dolphin tank about 20 years ago and it's still in use since I sold it. It leaked once moving it coast-to-coast and cost less than $100 to repair. I know other hatchery owners that have Dolphin tanks that have been in constant use for 10-15 years.
I don't know if they're better quality than other manufacturers but, I can't find any negative issues with their products be it aquariums, culture tanks, raceways, filter boxes, etc.