From everything I have read and experienced, they are the best rad fan on the market right now. They certainly are the best fan for air coolers.
Rear, Top and Bottom fans
While in last year's air cooler roundup, the 120s crushed the 140s in this test this year the 140's swept the floor with the 120's taking 4 of the top 5 spots. Air coolers present a tougher challenge than rads due tot he tighter fin spacing.
The Phanteks PH-F140HP/TS is the clear winner in every respect. It edged out the new Noctuas every step of the way, delivering the best overall results of any fan we've tested thus far. To top it off, it had cleanest, smoothest sound of all the new fans in this roundup. If we had to start from scratch, this might be our new reference model.
The fan tested in the SPCR test is the same blades, bearing and motor but has a different mounting frame. The did a 2nd round where an Antec fan edged out the Phanteks in thermal performance by hair but it's motor made that annoying ticking sound.
It often feels like Phanteks can do no wrong. Time after time, they deliver products that are either clearly top of their class, or merely arguably the top of their class. The new breed of fans, the 140XP and SP, do nothing to change that. Construction and performance are spot on, while noise to air movement is excellent. I have been fortunate enough to have been using seven of these in a build for the last month, and time has done nothing but make me like them more.
As case fans, the 140SP and 140XP are very controlled, and able to move excellent amounts of air through the case. This would be expected given the specs, but what is not expected is how quietly they manage to do this. First off, there is no discernible mechanical noise from either iteration of the fan. The bearing is dead silent, and there is no ticking, buzz or hum often associated with PWM present in the 140XP. The other factor is the actual pitch of the fan, which is lower than most 140mm fans we have encountered. There is no whine or high pitches of any kind. This makes the 140SP and XP far less intrusive even at higher speeds. At lower speeds, the air movement is substantial, but even in the front intake position there is no real discernible noise until ~850rpm, and they never become distracting when pushed beyond that.
While the fans are essentially the same with PWM added to the F140XP, that also adds some perks. The PWM control allows the F140XP to be run all the way down to 300rpm for absolute silence. The lower speeds also allow the static pressure to increase ~15%, making them an excellent choice for 140mm factor radiators. The 140SP serves very, very well on radiators also with good static pressure and low noise.