Try:

• MinShadingRate: 0.2 is a very popular setting here but I usually use 1
• Pixel Samples: 9. Will be pretty slow but edges will be very smooth
• Post Filter Size: 4
• Post Filter Type: Sinc. Your image will be very crisp; Gaussian / 3 will look more like film

There is a huge anti-filter bias in the forums, so most people leave theirs set at Box / 1, which is about the worst filter setting you can use especially since you can't turn off the filter. Blurs everything indiscriminately.