The demos only appear to be on the Roland keyboard clubs site, they are not on Roland.com as of yet, so as Abacus rightly puts the quality is a low bit rate. Maybe a model was lent to someone for those demos?
I know one of the UK shops already has one. Roland will possibly put different demos and maybe a video shortly on their web sites. The E80 is supposed to be out late June/early July in the UK from what I'm being told, so Roland still have a month to get into shape, but as usual they always leave it late to demo their models