Overall it looks great, nice textures and composition. The keyboard lacks either illumination or detail, but maybe that is intentional.
You could achieve lower render times using a better sampling strategy.
Use Additional Samples of at least 2, reduce AA Samples to 2 (unless there is a lot of very fine detail), and lower the Threshold value, then use as many passes as you feel necessary to give a clean image. Using only 2 samples per pixel, the first pass will render quite fast, and subsequent passes will resample only the pixels which differ by the Threshold value. Subsequent passes will sample less pixels each time, thereby reducing the overall render time.
Reducing Pixelwidth will give a sharper looking image, though don’t go below 1.2.
Final Gather bounces is probably a bit high. Samples at 32 possibly is as well, though I didn’t see the test renders.