Quick turning measurements (54" deck on concrete)
GR2120 uncut circle: 37", turning radius: 19 1/4"
I mowed with it for about 20 minutes.
My initial thoughts comparing it to a BX: Much smaller operator area, harder to get on and off, as expected, but just mentioning for anyone who is wondering. I am 6'3". The deck lift control could be in a nicer location, it is too far back (and on the wrong side lol), it feels slower in both forwards and reverse, the steering effort feels.the same (very easy, one finger control), engine is very very smooth at normal operating speeds. Cut quality seems the same as the BX so far but the grass isn't tall enough to really tell for sure on that overall, I went up and down some small hills and it done fine, there's no way a 2wd tractor would have done it, you can "feel" the glide steer kick in when turning, it is very subtle but I only noticed when paying attention, it definitely works great.
I took a few pics with the BX: