The Zurich Airport web site has a section on the spotting/photography facilities.
http://www.zurich-airport.com/ZRH/?ID_site=1&le=2&d=cnt/ATRP/EN/trp_terrassen.asp&sp=en&u=1&t=Observation%20Decks&ID_level1=6&ID_level2=17&a2=17
I went up onto one of the viewing areas at about 15:30hrs…. Dead as a Dodo!! but the view was very good. In fact a lot of the pictures from ZRH on “Airliners.net” are taken from there, so they will give you an idear of the view.
My pictures from ZRH? My six year old got hold of the camera and deleated them all!!!!!!
Enjoy ZRH

Rgds Cking