Hey Jams,
Yes you can see a big improvement, it really depends on what you’re switching from and too.
Going from a single piston GM or Must II sliding caliper, to a 4 or 6 piston aftermarket caliper will gain a lot of heat absorbing/shedding capability. That will make your brakes less likely to fade. Also the calipers tend to be more rigid so the pedal feel is better. Pad changes are easier and depending on the caliper can have more pad area and even be lighter.
They also allow the use of a larger rotor, which can also be an advantage if your seeing overheating issues with your current parts.
A couple of questions:
What do you have?
Why are you unhappy with your current brakes?
What are you thinking of doing?
Below is my current revision. I’m working on a one piece hub/hat/knock off deal now.
Jason