Okay, the first thing to point out is that this product is HUGE. It's a massive chunk of granite and is quite weighty. If you're a diminutive string-muscled individual then you'll need some kind of servant to move it round the kitchen for you.
That being said, all that weight means it's incredibly robust so you can really pound and grind those herbs and seeds. The dark granite means that it's really easy to see what you're doing and the smooth surface means you don't leave precious ingredients behind when tipping into your cooking.
Easy to clean
Easy to use
Pretty (aesthetically pleasing)
Hard to steal