So first off, let me say I ordered this with my Prime account, and it comes with free 2-day shipping...it got here in 1 day. I immediately took it out in the frontcountry for a day hike with the dog to give it a test in the field.
We made it to a nice frozen shoulder of the Rattlesnake Creek in Missoula. The temp was below freezing, i'de say 20-30°F, or somewhere around there. I chipped through an ice shelf on the creek and dunked the bag into the ice cold water. Filling it was easy with the current but I can see some wishing it came with a bigger bag because it doesn't look like much when the bag is filled. I use a 32oz Platypus bag I have, and carry the included 16oz bag as a backup! Anyway, I screwed the filter onto the bag, tipped it upside down and water came out with a very effortless squeeze. After I got done laughing about how simple this was, I gave my boy Yoshi a drink as well (my English Bulldog). He also took to it well, as he's a big fan of drinking from water bottles anyway. So yeah, this is a dog friendly design!
Also out of curiosity I affixed the straw directly to the filter and drank directly from the creek and it was quite easy to do. The amount of suction required was similar to drinking a milkshake, and the flow rate was surprisingly great. At that point one can either shake the filter free of the water still inside the filter, and/or blow through it providing the same effect. (I should note that if using this in freezing temperatures, to prevent the filter from freezing after use, you will want to keep it on or near your body's core).
When I got home I did the back flush with the syringe twice, and the thing flushed perfectly. This thing was a piece of cake to use, and was exactly what I was looking for to carry in my Heli Pack. I would recommend this filter to anyone!...and for $20, you cannot beat this. Plus you get a bag, straw, and syringe with it. Buy one now!
Anyone with questions, feel free to ask/comment. Glad to help.
UPDATE: After 18 months of steady use, this thing is still running strong! I have also come up with a cool addition to this water filter...I removed the sticker on the white middle section and I have replaced it with about 5 feet of standard width 1.88" DUCT TAPE! Using the filter AS the spool for the tape, allowing this filter to be a multi-purpose device. Some people will carry duct tape with them as a emergency repair kit, but we all know duct tape has a million uses, it's the cousin of paracord practically. Trust me it is cool, with the duct tape wrapped around it multiple times, the tape will eventually be flush with the filter end caps and not look sloppy at all. Plus it's a cool way to personalize your filter with a color or pattern to match your kit. If your a little picky like me, I didn't exactly want a "blue" item with my stealth gear. Anyway, this method allows you to carry a decent amount of duct tape spooled around an item you are already carrying, and not taking up ANY extra space than the filter already is using inside your kit.
Why not carry some...it might come in handy sometime.