It works. It really works.
I think my husband and I have spent more time trying to get stuff to fall out of the Gyro Bowl than BB's actually spent using it, but the bottom line is, it works. Not a Cheerio has been spilled since we got this little contraption. In fact, when I had to empty it, to clean it, I had one heck of a time.
I don't think BB needs this bowl - he's beyond careful when carrying things - but he enjoys the oddity of it. In short, I'd buy it again and I think it'd make a fun gift.