Product review (4 stars): Works as advertised
There are 2 downsides to this product but they are minor.  First, once installed it makes your faucet a bit more cumbersome as far as swiveling the arm back and forth.  Second, if someone pushes the eyewash button valve by mistake, you can expect your hands and arms to get drenched the next time you turn on the water because it will flow out the eyewash nozzles unless you remember to check the valve every single time.
These issues aren't design problems and are really minor compared to the problem the eyewash station solves.  If these issues are too much for you then I recommend installing a separate, dedicated eyewash station away from the sink.