The December 2008 issue of PC Pro (out today for subscribers) has a review of the PRS-505 on page 68. It is also available on-line at
http://www.pcpro.co.uk/reviews/22423...er-prs505.html.
The review is generally positive, whilst also pointing out most of the weaker areas of the device.
PC Pro is, I believe, the largest circulation monthly magazine for IT Professionals in the UK.