Risk using amp Wattage than speaker rating?

I'd like to upgrade the amp for my Vandersteen 3A Sigs, but am a bit confused on whether or not I need to stay within the band of wattage (100 - 200 into 8 ohms) that is *strongly* recommended in the manual. I've read several articles/blogs/forum posts stating that exceeding the recommend power range for a loudspeaker system should be of a little concern, as long as you don't "push them too hard". What exactly does that mean? How much risk of damaging my speakers would there be if I used a 300 W/ch (into 8 ohms) amp with my speakers? I have a fairly large room, if that makes a difference. I appreciate any advice, as you all seem to be very knowledgeable about audio and have a lot of experience. Thanks, Rob