I just checked the specs on the Profoto site and they list the range of the Zoom 2 as 45-100 degrees. Interestingly they don't list the specs for the Grid reflector on the site but they are on the reflectors. They're 45-95 degrees, which would support my experience that they have a slightly softer fall off.
I use my old Balcar and Comet grids which I bought entire sets of for about the same cost as a single Profoto grid.