Stu: I'm waiting on Microsoft to receive stock of the i7/16GB/256GB model. The i7 models seem to have been unavailable for a while. Maybe due to the backlight bleed issue?
I contemplated a Macbook, but when those normally supporting and using Apple also lean towards the Surface Pro it just didn't seem to be the right way to go. ;-)
There was a thread on reddit about i7 SP4s being held until a certain update was applied to all i7 models.
https://www.reddit.com/r/Surface/comments/42xj0h/surface_pro_4_with_i7_not_being_delivered_due_to/