What are the dimensions on your 25 gallon?
I think with the light sitting on the tank as intended, you'd be fine with up to a 12" deep tank that's no more than 12" front to back, probably even with bright light coral.
For a deeper tank or the brightest light corals, I think I'd use two units side-by-side.
From the stats, it looks like this is going to give you a very white light compared to what you see just about everywhere these days. (The "rule of thumb" ratio is 2 blue LED's per every 1 white, or 2:1 in favor of blue. Although they are "bluer whites" this light is 1:6 in favor of the white.) This is fine as long as you're aware of it.
I would also spend time checking out other available options, if you haven't already. The market is stinking with good LED lights these days. :)
-Matt