Is the Sigma 30mm F2.8 the best lens for NEX? Your thoughts

SLRGear did a review of this and noted the following "It's worth noting that the focusing lens elements that move are loose inside the lens when not attached to the camera so they make a rattling noise: Once attached to the camera the linear focusing motor is engaged and there is no more noise.". The review is at http://www.slrgear.com/reviews/showproduct.php/product/1483/cat/30 .