-Standard Fullfield IIs (not the TAC series) offer finger adjustable turrets; Prostaffs require coin adjustment. Advantage Burris.
-Glass is probably about even between the two, with possibly a slight advantage to Burris.
-Nikon has the BDC reticle, Burris has the Ballistic Plex. Advantage Burris IMHO
-Burris is typically slightly more expensive than ProStaff for identical features. Advantage Nikon.
The Nikon Buckmaster line is probably a better comparison to the Fullfield IIs, based on price for regular 3-9x 40mm scopes. They have target styled turrets in addition to better glass that is fully the equal of the Fullfield IIs.
In short, I'd prefer Fullfield II over ProStaffs, but would prefer Nikon Buckmasters to either.