Manufacturers like to keep valve clearances as small as possible, for the simple reason of top end noise. If you ride near redline a bit, though, slightly more clearance is helpful. Causes less wear, and handles the top end a bit better.
Unless you are looking for quietest engine you can have, and don't spend a lot of time stressing the engine, the outside margin of the clearances stated are better, and sometimes, even a little wider is better.
