I've been holding on to my brake upgrades I took off my RS before I sold it. Now with the new wheels I could put the 4 pots on:

Subaru 4-Pot install (http://www.scoobymods.com/forums/showthread.php?s=&threadid=3105)

Larger Legacy rear rotors (http://www.scoobymods.com/forums/showthread.php?s=&threadid=3106)

Speed Bleeders (http://www.scoobymods.com/forums/showthread.php?s=&threadid=3104)

how is the brake balance with the 4 pots up front, and the H6 rotors in the rear?

This is the same setup I had on my 99RS the balance was fine on the RS and what limited time I've had with them in the XT it seems nicely balanced, stops are smooth and linear with regard to pedal pressure and how quickly I stop.

Peaty

PS: the larger rotors on the legacy are all the same from 00+ on up, both the H6 and H4 have the large rotors. Not sure how the H6 only thing got started.