I have a 2006 MCS GP with 14mm lug bolts. I am going to switch from lug bolts to wheel studs. Should a use the M14x1.25 to M14x1.5 conversion or the M14x1.25 to M12x1.5 conversion kit?

I am thinking the M14-M14 kit would be better but it would be easier to use the M14-M12 kit. Here is my setup:
I have stock GP wheels with holes for the 14mm lug/stud.
I have 15mm spacers that work with the 14mm lug/stud.
However, I am going to add Wilwood rotors that currently have holes for 12mm lug/stud. I have access to a machine shop to drill (or mill) the rotor holes to work with 14mm lug/stud.
I will track the car.

If there is no disadvantage using the 12mm stud (due to less strength, smaller lug nut fit in wheel, slop in wheel hole, slop in spacer hole) than that would be the easiest way to go because I do not have to drill/mill the rotors.
However, if the 14mm stud is better than a 12mm stud (M14-M12 conversion stud) then I will drill the rotor to fit the 14mm studs.

 

I went with the 14 mm -> 12 mm conversion studs and have had no problems in the past 50k miles and many autocross events.

I don't think anyone's ever found a good reason for why MINI went to the 14 mm bolts in the first place. If there were a rash of the 12 mm bolts failing, I think we'd have heard about it here in NAM.

 

So it looks like the 14 to 12 mm stud conversion would be the best way to go since I will mot need to drill/mill larger holes in the Wilwood brake rotors.
Anyone know of any disadvantages with the 14 to 12mm stud conversion?

 

I ordered the M14 to M12 mm conversion kit.