Bought the NAU 460 to replace a Jensen 760 amp in my 20 foot runabout boat. The Jensen died about 2 months after its one-year warranty! The NAU 460 appears well built and sounds very good for its price. It survived its first summer boating season, which is when it's driven in 90+ ambient temps and humid (but minimal direct water contact) conditions. The only reason I am giving it only 4 stars for overall and durability is that I've only had it for 6 months so far. We'll see how long this one lasts.