Sleek indeed does not translate to slim. Sleek usually refers to elegance in design. From what I see here, it is just a typical boxy case with grooves on the side. These are common design styles in this form factor, which is unfortunate, because there's no creativity anymore. Do not be mislead just because there's an 'antec' branding on this.
I'd rather call these cases 'sleek' than this one instead.
http://sohoo2008.en.made-in-china.com/product-group/FMxEzymAufkJ/Slim-Micro-Mini-ITX-catalog-1.html
http://www.nesteq.de/gb/products/cases/ms550/
And i suppose, if you slap an 'antec' or 'lian-li' or any known brand onto any of these cases, you people will drool over this and call it the best thing since. Come on people, you know better than just being biased!
I know, these are the same people that drools over a Lian Li PC-Q30 case for some 'odd' reasoning. In the case of PC-Q30: ODD yes, cool no!