According to tests we have done, coolers with horizontal heatsinks have a lower performance compared to the best "tower" coolers. Tuniq Propeller 120 was no exception.
Even though it has an excellent construction quality, it achieved an average performance, comparable to cheaper tower-design CPU coolers. Note, however, that it performed better than most coolers with similar design, like Nexus LOW-7000 R2, Thermaltake ISGC-400, SilverStone NT06-E and Noctua NH-C12P.
Its looks are very cool with the blue-glowing fan and its noise level is very low, virtually inaudible when in low speed.
Being an expensive cooler with average performance, we cannot give it an award seal. But if you are looking for a cooler with a horizontal heatsink with high-quality construction, nice looks, low noise level and capable of cooling a medium- or low-TDP CPU and price is not an issue for you, you can buy Tuniq Propeller 120 with no fear.