I had a deezee 8 ft bed box (technically went back by the tail gate, I used it on my trailer) and it was made very well, I would have to think their standard boxes would be the same.
I currently have a better built (which is lowes/kobalt) which is not as nice as my deezee, but its holding up just fine for less than half the price. As stated the hinges could be nicer, the gas shock could be better, but it's cost efficient.
If I had the money sitting around I'd buy another DeeZee.