Just chiming in here.
Where in north Phoenix are we talking?
I live in Cave Creek (I know they are not building it for me) and I am OK with the downtown location. I go to Sun's and DBacks' games now and will continue to.
Someone mentioned the Talking Sticks Fields area. That would be about the same distance as downtown Phoenix for the east (and far east) valley fans. It may be a little faster as they can take the 101 north instead of the I-10 or whatever they take to go downtown. Based on where the west siders live the Talking Stick Fields area may be quicker.
Ideally, I would like to see all for facilities near downtown. It would be a boost to downtown and they could work out shared parking. I know that will never happen as it is too late.
My first choice for our DBacks would be downtown (even though my 2nd choice is better for me) and my 2nd would be somewhere on the 101 (the Scottsdale area).