I've done both. The Mark 8 (see my old article on this site) on my '93 and the PBR on my '94. I'd say maginally the PBR's are better, in as much as the rotors seem to last a bit longer before warping. Both upgrades require the '93 + spindles; but of course I didn't have to do that on either of mine. If you are on a tight budget and don't have aftermarket (see thru) wheels to worry about appearance I'd just go to Advanced Auto and buy their $20 rotors. Even the KVR cadmium plated & crossed drilled rotors at $100 ea. don't seem to last much longer before warping. On the other hand if your calipers are bad and you need a brake overhaul, then I'd probably recommend the PBR's. I got mine used from "mustangparts.com" - they are actually salvaged from crashed 2000+ Mustang GT's. Mine came with the calipers, frames, pads, hardware and hoses for $99 a pair; but I don't know what's available currently. If you go that route then look at the article on TCCOA, because you'll need to either grind down the side of the passenger banjo fitting or (as I did) grind a little off the caliper housing to accomodate the stock brake hose.