I havent bothered with Wi fi but for watching on its a treat, I copied some old films from my Archos AV420 quality is watchable but not as impressive as they appeared on the AV420.
The difference between the AV420 and the 704, the AV420 does have the better picture BUT try watching football, subtitles on 420 or the 500 600 series and thats where the 704 pips it. It does have the looking through stockings appearance that some one mentioned and all depends on how close you are to the unit, but you soon get used to it and to be honest i hardly notice it now.
Overall im impressed it looks sexy and the picture although not as vibrant as the 420 is a treat, my machine will not be going back for a 600 series due to the reasons above IE watching footy, films with subtitles ect.
My only tip is dont waste time transferring old recordings from a AV420 over onto it quality wise its like watching a vhs