I got green bags last month. And so far they've worked for me. I've had mushrooms in them a week, so no sign of going bad, usually I can only keep mushrooms a few days and they start turning. I've got a haed of lettuce testing now thats been in there over 23 days, still fresh and crisp. I tested bananas on the counter one in the bag one out, I got 3 extra days from the banana in the bag. Celery, the celery I used up for Christmas cooking I've had over a month, had it a week when I got the green bags, still fresh and crisp. Now why didn't I remember to put my carrots in there and test them too. I tested some fresh green beans, ended up cooking them before they went bad, but I did leave 5 in the bag and they went bad 2 weeks after I bought them, as compared to one week without the bags. Now I'm sure results may vary depending on how you store them and where in the fridge you store them, how fresh were they when you bought them and how ere they stored before you bought them, moisture. How well the green bags work are going to depend on a lot.
I haven't tried the bags for cheese yet, but I have been using the bread bags, and actually they work. I can't eat a whole lot of food at once, so preserving it longer is important to me. And I've had mini bagels in the bread bag for over nearly 2 weeks, still fresh, so sign of wanting to go bad, I've got 2 english muffins left that I ahd before the bagels and they're still fine too. I've never gotten this from a regular bread bag.