He's showing you a simple setup that he sells...plain and simple. Without going into the math (hat tip, ntsqd), he's in business to make a profit. The simple single piston calipers are cheap to produce and market with likely a larger profit margin, and he can make bank off the simplicity of design, which sells more units, and to him that's worth more profit. Think about this aspect though--SSBC has been in business selling aftermarket brake systems for at least three decades. Take a look at their drum to disc kits--they're multi-piston fixed calipers (except for rear disc kits), and strangely enough they very much resemble those 40+ year old KH designs. This is not a coincidence. When properly maintained, they are no different than any other braking system and are plenty reliable. Newer vehicles benefit greatly from CNC machinery and other processes which can faithfully reproduce those complex designs for cheaper per unit cost and that enables our favorite manufacturers to use better parts and such on the cars we drive. I can't speak for a new Challenger or Charger, but I can say with certainty the new Mustangs use multi-piston calipers even on the low option base trim models. Again, this isn't a coincidence...it's better equipment. I agree that the single piston caliper setups are easy to maintain and swap to, and for the vast majority of classic car enthusiasts, they offer more than satisfactory performance at a low cost with readily available repair/replacement parts. But, just like we all know, cheap rarely means great and as long as you're not clouding your own judgment in that perspective, you'll be fine. Not everyone wants to be king of the world, not every hot rodder or classic car enthusiast wants to drive a $80K pro-touring ride despite how cool they are...most of us want just to drive our toys and enjoy them. Simple systems like the '73-up brakes fulfill that market segment, and as long as people are driving A bodies with front drums with a desire to upgrade, those systems will exist. But, for those who want something different, those systems will be available too. Speaking ill of either setup is just pissin in the wind...like has been said, numerous times on this site before, pick your parts, pay your money...just be aware of what you're dropping the money on...