I thought the same thing before testing them myself....... The compressor cover design is far superior to older designs. The HKS 2530 was way ahead of its time when it came out.....The same goes for this turbo.
The graph below shows your 2530 car stick shift vs my exp90 car automatic. If you keep in mind the automatic transmission running 250 psi line pressure that robs a crap load of power you can see the low end would be similar or better on a stick dyno and after 4000 RPM all bets are off and it shows superior performance without question.