Seems to be a good site. I like the fact the entire site is using SSL and not just the checkout, the SSL implementation gets a solid A from ssllabs, and the privacy policy looks sound.
Not sure why its rated low, but in the rating of the site, the option to disagree with 'Poor Customer Experience' is an option, so that may be a clue. I have not ordered from them, so I cannot attest to that or not.