Have several systems tested by vacuum bags, as for my purpose was only viable system and the future remains Zebco in use! The following conditions were considered: The system should work without electricity (with a hand vacuum pump) and be operational almost everywhere. The bags should not weigh too much as possible and should not "thick" or have heavy valves. These conditions are all met. So why "only" four stars? - Because the "lip seals" of Zip-Loc are quite sensitive. Already in their first assignments were 3 of 22 bags (3 different sizes were in use) are not vacuum packed tight binding, although definitely everything clean, "dust-free" and was piled neatly. After first use (admittedly a tough application in outdoor and backpacking area) were 13 more bags no longer tight, because the sealing lips had defects, either the bonding / welding to the bag dissolved, or in three cases broke the seal itself (mind you longitudinally, not across wrinkles!). In all cases, not the valves were leaking, but the Zip-Loc! In addition to a 6-liter bag (clothes), and ten 3-liter bags (dry food) many 1-liter bags were used. Our backpack volume has through the use of the bag significantly (!) Reduced. (Tip for air travel: rolls of toilet paper, towels and other bulky parts are very small and handy). Conclusion: To foods etc. to package itself and kept in the freezer or a space-saving to store, occur without mechanical high loads, the bags are certainly well suited. Generally, they are also robust enough, but the reusability is mE limited and the bags should be controlled depending on the application given if after a few hours or a day or two after vacuuming again.
My personal wish to the manufacturer (in addition to improving the lip seal): bags in even more sizes or dimensions, because there are many uses, not only for anglers!
