I see what you guys mean about the whole system being a bit spongy but I don't think we can do too much about it. However I did upgrade my worn front brakes about 3 weeks ago with a PowerStop combo from RockAuto (slotted/drilled rotors and ceramic pads) and the difference is quite dramatic. So far I am very happy with my choice.
Also, it's very important to bed your new pads after you install them ... drive around 10km or so to make sure nothing is loose then find an empty road, accelerate to 60 - 80 km/h and brake hard to a complete stop. Do that at least 20 times, and keep checking that there are no cars behind you before you hit those brakes!