This is a tough question....mostly because I don't know how any of these bikes suit me.
The upright position sucks for me because it puts a lot of weight and pressure on my lower back and butt....but is easier on the hip flexors and legs. The aggressive SS position on my gixxer alleviates the lower back/butt problem...but fatigues the hell out of my legs. Also, the wind protection is better.
For the moment I appear to be a supersport kinda guy....so I'll go with the ZX-14R:
I sat on one of these and the seating position is a little more upright than a typical SS....but definitely not as upright as a typical standard. Also...I'm not really a busa fan
