Here are the measurements of the handlebars using this handy diagram from
JP Cycles.
Width: 31.5" incl. grips and weights
Rise: 6"
Center Width: 6.5"
Pullback: 6"
The stock GZ250 is listed as 28"W - 7"R - 6"C - 10"P, so your eyes are most assuredly correct.
They are comfortable, although, like the exhaust report, I have no experience on a GZ250 with anything different, so my opinion is limited.
I do like the cafe-look too, so I'm curious as to how the bike would feel with drag bars.