How to choose brake cables
I usually get the cheapest stainless steel cables and housings from a reputable manufacturer like Shimano, SRAM, BBB, Jagwire, Avid etc.

I very much doubt that expensive cables for >10€/piece will significantly improve braking performance. Especially if you are already happy with braking performance.

Proper cable installation&amp;routing, matching brake lever to brake arm ratios and high quality brake pads will have a greater impact than SuperUltraSlick™ cables.

Edit: As Rider_X points out in the comments, some brakes work better with stiff cable housings. In such a case stiff housing like Shimano SLR or even Nokons (expensive) are a good idea.