I'm not going to tell you that the Hyperflow doesn't get harder the more it's used. This is true and something we have talked about and trained on at our recent sales meeting. This is most definitely a concern for MSR and you can expect some updates in the future.

However my own personal experience has been positive. It is a small, light and fast filter which is consistent with MSR's claims. I've timed myself at almost 3L per minute although I was really trying. It has the capability to do so, but that will diminish, just like every other filter on the market, the more you use it.

It might be worth checking out the HyperFlow FAQ page. Often the main culprit is that the backflushing is not performed properly. Cascade Designs is also preparing a video that will be available sometime around the first of September which visually shows how to properly backflush. This video will be available under the water treatment section of their website.

I find the introduction of the Hyperflow to follow many of the more technical aspects of the MSR products. As you look back at when the Whisperlite was introduced, many felt the steps needed to operate, clean, and maintain that stove were beyond the scope of the average backpacker. However today it has become a standard piece of gear. The Hyperflow falls into this same category. It is true innovation in backcountry water treatment that will stand the test of time.

The AutoFlow and the CleanStream are gravity filters using the Hollow Fiber technology. The benefit here is that the user is not forcing the water through the membrane, but rather allowing gravity to do so. Thus the microscopic particles sit on the surface of the membrane much more loosely and, as a result, are much easier for them to be dislodged. Thus by simply reversing the flow of the water through the filter, most of the "stuff" is removed. Therefore the gravity filters have a larger capacity based on the fact that they can more effectively be cleaned. They aren't as light as the Hyperflow (10oz. vs. 7.5oz.) nor as packable, but they do a very effective job at 1.5L per minute without any pumping, etc.

I've used both the AutoFlow and the CleanStream in the dirty Colorado River and was very pleased with how well they worked. They are fast and when backflushed, I am amazed at how much of the dirt is removed. Just like the Hyperflow however, it does get slower the more its used, even when backflushed.