One major disadvantage to the ULA's filter is that it's not field cleanable.
I just ordered an Amigo and did some homework before I ordered. The Amigo uses a PUR Hiker Pro filter which is indeed field cleanable. I went to REI and took one out of the box for examination. It has a pre filter mesh type screen around the main filter body that is easily removable allowing access to clean both the pre filter and main filter. The only thing about the Amigo that I admit I may not be crazy about is the water bag. Looks like it may be a bit cumbersome to fill. But we'll see. If I don't like the bag I may replace it. Hard to beat the 7.5 oz total weight. I had considered making my own gravity system but the cost of the Hiker Pro filter element alone is $39.95. I could have easily spent more in materials than the complete filter from ULA.
In regards to the Hyper Flow weight of 7.8 oz., I have read that this total reported weight is for the pump only and does not include the pre filter or hoses required for operation. Can anyone verify the total weight of the complete filter with hoses, prefilter and any other items necessary for field use?