The enlargement is not so overwhelming (factor 2.8 is really not very much) and the resolution of the display (Canon 60D) then can already detect pixels. Therefore you have no real profit because, unless you so block out sunlight.
As sunlight blocker it may be okay, but I suppose it's better a sheet foam rubber or paper. This thing is bulky (not similar to fold and as big as a lens) and provides for little benefit. When applying for Videography that might be different, but I did not think of it.
