I normally buy Noctua fans, but recently came in to a number of Antec Tranquil 140's. I was very impressed with them. Compared to a NF-A14 they are more suited as a case fan, because they have a 10% lower static pressure but a 10% higher flow rate. The Antec are 2db louder, which is not unusual considering the higher flow rate. The only major difference is the minimum rotation, which is much better for the Noctua. That's 300rpm for the Noctua and 450rpm for the Antec. Both have a max of 1500rpm, which is going to be pretty noisy for any fan. The Antec are significantly cheaper, though. For a case fan, I would have no hesitation in recommending them.