The difference in stopping power between the 13" PBRs and the stock brakes is huge. I've never driven one that has been swapped to the Brembo's, so I don't know how much of an improvement those would be over the PBR's, but in my opinion, for a street car, the 13" PBRs are sufficient. Even on the Lemons racecar, we ran the 13" PBRs, and repeatedly slowing down from 135 on the straight to about 45 for the first turn, over the course of 2 days, they never faded. On the other hand, the stock brakes on that same track were heating up so bad that the brake pad actually welded itself to the caliper piston from the heat!
Nobody is arguing that the fixed calipers aren't better, but are they enough better to warrant 3x the price? On a high end build, or a track car, maybe, but on a street car, I say probably not. And yes, you will enjoy the 5-speed swap much more than a brake upgrade, but then again you generally don't upgrade the brakes to enjoy them, but rather to be able to stop in time to safely enjoy the other upgrades.
-91 Cougar LS, coming soon, complete overhaul
with a 427" Windsor.
-90SC 5-speed, MP2, coated rotors, double intercooler, 15%OD, ported heads, comp stage 1 cam, 85mm TB, 90MM LMAF, 80# injectors, soon to be transplanted into...
-90 XR7 5-speed black on black w/sunroof
-98 Mark VIII LSC, Procharger P600b, TR3650 swap and 3.73s.
-70 Torino GT Fastback project car. Needs EFI and a manual trans, but I'm not sure what motor to go with yet.
-"Your buddy Mike is INSANE!" -ClintD's dad