I bought this stem because I was looking to move my bars down and out just a bit but found that 6 degree stems took me down too far from the short 17 degree I was using. There are sites to calculate the difference in position a given stem will place your handlebars, Id suggest you use these along with a proper bike fit to get the right stem for you.
The quality appears to be top notch (as would be expected from Shimano) and the stem is indeed quite light compared to others.