Opinion about scythe slip streams?

I don't know much about the 140mm version, but what other 140mm fans are easily available to you? I really do believe that there are similar or better options performance-wise and definitely lifespan-wise. However, I do have experience with the 120mm 1900rpm 110cfm model. It is a good fan for the price, blows a lot of air, is only $7 USD (in US), is actually pretty quiet compared to a lot of fans "rated" at a much lower Decibel level, and can last a very long time if you are diligent about maintenance.
First, before you even use the fan you need to add a bit of light oil to the bearing, which you can get to by gently peeling the sticker off the hub of the fan and put a few drops in and replace the sticker.

A few things that you should know...
- The Scythe Slipstream fans can only be mounted vertically (i.e. Front intake/rear exhaust) as horizontal mounting (top exhaust/bottom intake) will force the bearing to run dry and kill the fan quickly
- While it does blow a ton of air, it has very low static pressure and an unfocused airflow pattern, which means that it blows air in a large cone shape, while fans like Scythe Gentle Typhoon/Silverstone Air Penetrators/most 120x38mm fans blow in a much more directed fashion more like a cylinder.
- It works best in a position where there is minimal obstruction via case-fan grills and/or filters, but it can be used in such positions just expect a decrease in airflow

The ideal location for these fans is as a rear exhaust, side-panel intake/exhaust, an interior fan, or as a front intake that doesn't have any hard drive bays between it and the interior of the case.

The 140mm slipstreams move good air and do it without being too loud.

However, they are crappy sleeve bearings and are prone to die. If you use them, buy at least double what you'll think you'll use. One dies on me about every 3-4 months of 24/7 use.

They do have a lubrication port on the back and they are plain old sleeve bearings, nothing special, unless they have been significantly revised recently.
Edited by Blameless - 8/19/12 at 10:04am

Warranties on fans are a joke, especially cheap ones. You'll pay more for shipping than the price of the fan itself if you decide to RMA it... I suggest you go for some quality fans now with nice bearings instead of trying to go on the cheap side. Two 7,50$ fans that will last a year each are worth the same as a 15$ fan that will last for 2-3 years.

Slipstream are a good choice for places where they are mounted vertically (blowing air front-to-back) but not so much if mounted horizontal (blowing upward or down). I would suggest getting the Bitfenix fans for the horizontal fan mounts and Slipstream for exhaust. The Kama Flow 2 or Bitfenix would be great as intake fans that have to blow through the HDD bays.