I've just left a review too (Amazon UK) :
Buy Slingbox at your peril
Slingbox (more specifically Sling Media) go from bad to terrible. They now are injecting Ads into the browser based desktop viewer. It totally ruins the viewing experience.
Sling Media ignore their customers, they just don't care about them. It wouldn't surprise me if the just switch off the whole system one day and leave you with useless box. Avoid.