Relativity
It is odd that a $500 device with only 720p resolution would be described as "outstanding". It seems that there is no absolute definition, it depends completely on the reviewer's disposition towards whatever is being reviewed. If they have already decided they like a product, then such descriptions will fit. But (I suspect) only until something better comes along: a 1080p projector, for example.
As such, we have to wonder what is actually being reviewed? Is it the gadget itself, or the progress in technological development. It would appear to be the latter.