I ordered this brand, as well as many others, as lots of reviewers seemed to have problems with the valve keeping the air out. I don't actually think that's the problem, in general.
Sturdy bags, really good quality, and every single one of the them worked well. One note though: for all of the ones I packed, I made sure to press every millimetre on the zip lock - I think that it the key to getting it lasting well. Out of 20+ packed so far (various brands), not a single one was faulty.
Would recommend!