15mm spacer???
That is ridiculous? What brakes were you going to run..... reventon brakes?
At the end of the day, people can buy what they want? But i have bought 3 sets of brakes now! The 312 upgrade was nice, as it bit a little more! yet for the money, not worth it! And dont look good under a big wheel!
Where as 4 pots..... are affordable, can be done to a small budget, not hard to get hold of... and look cracking under a wheel!
Devilz..... if you want a very cheap brake upgrade, i would say buy them! But you will be dissappointed for the money you spend!
I would recommend do a 4pot conversion in stages! Buy the calipers, then the discs etc etc. That way you dont blow money all in one go! Up to you pal!