Just to add ... The decision to add the rear Brembos was not for bling but for brake bias.
BBK-only fronts shifts the bias even more forward. I wanted to keep from making the fronts essentially the only contributor under heavy braking.
Spring upgrades and the BBK rears provide brake bias and weight shift control.
I would recommend getting a rear BBK to those getting fronts. Need the springs or coilovers from the start.