Something doesn't give me a "warm fuzzy" about that supply. Reviewers indicate that it puts out as much as 5.4v under minimal load, and it drops to 4.8v when loaded. This is some pretty poor regulation, and could result in a severely shortened LED lifespan.
These cheap supplies are also grossly overrated for current output. The 3A rating is probably the point at which it melts down if used near that for more than a second or two. If you have a lot invested in LEDs or other devices, it doesn't make sense to go cheap on the supply. It can cost you a lot more in the end.