Their cheap power supplies are just that, cheap power supplies. If you use them to power a really low power system they may live on for 4 years, if you bring them close to their rated load on a regular basis they arent going to make it through the month. You get what you pay for, and if you buy a cheap aluminum box you get a cheap aluminum box, if you buy a decent power supply you get a decent power supply.
The only raidmax units i would even consider are their AE series, all of their other ones are significantly over rated, and many are still using passive PFC indicating designs that are several years old.