In all equipment, there are differences. Whether you want to pay for what you think might be a difference, in the end, is the difference. Half-bridge Korean designs are more complicated and require a lot more parts. The rest is sourcing those parts and manufacturing (location and labor). Example, the DS18 brand (not a commentary on DS18, just an example of two Korean models within the same brand that differ in price and why) has two lines that are Korean designs; the EXL and the Hooligan designs. The main reasons for the substantial gap in price in these same brand lines/models is material sourcing, and labor. DS18 has (at last glance) 4 Chinese build shops and 2 Korean shops. The Hooligans get their design, their parts and the labor, all from Korea = much higher cost. The EXL line, Korean designed too but the parts and labor, China = much lower cost.
Now the Brazilian full bridge designs use fewer parts (as part of the design, not inferior, just different) and the Labor is somewhere in-between. Consolidated manufacturing, low’ish labor cost, local Manufacturing/distibution relative to large markets, and fewer parts due to the design, = lower cost. Overall, Korean amps are more likely to tolerate voltage drops, use more sophisticated designs and have better technical specs (I know this is subjective, but overall) In a perfect scenario Brazilian amps due to their designs will out power most of their Korean/Chinese counterparts.. But if you lose that perfect (voltage) scenario prepare to drop some Cash. Korean amps are generally quieter, have high damping factors and are kind to voltage fluctuation. Brazilian amps tend to be more temperamental when it comes to voltage. If I’m doing all out SPL and I’m thinking watts per dollar, Brazilian all the way. Cost not the overall concern SQL, built like a tanlk build - Korean - Just my opinion.