Very nice! Those look great! Can you use the stock caliper mounting points or were brackets required? I've always thought the stock brakes on the XC90 were weak compared to other SUV's I've driven or owned. Do you have SS brake lines?
Where did you buy the brackets? The Brembo GT application catalogue for the S60 only has 332mm rotors with 4 pot calipers and you have the 355mm so where did you get rotors from and for which model?The front brembo 6 pot can be purchased from ebay, viva etc meant for s60 with s60 brackets and it fits the xc90.
In summary, the s60R brembos meant for the P2 model is quite similar to the XC90 P2.