the usual conclusion that i have seen is uv for a fo or fowlr = good, uv with a reef = bad
the uv will severely inhibit coraline growth, as the spores will not survive to attatch, and it is lethal to many of the micro organisms/plankton that filter feeders and coral live on. this is the main drawback to using them.
also there is some decrease in the effeciency of the bacteria cycle, but if you need to control algae or ich (both of which can be controlled with alternative measures if need be) then in a non invertibrate tank, uv should work fine for you.
do some searches on uv here on the board, you will find a TON of threads discussing the drawbacks and benefits of the units, and you can draw a conclusion more from there.
