I love love love the Kiinde system!! It is so easy to pump and turn my bags directly into bottles. We use the Kiinde nipples as well, and my baby loves them. We started out using the adaptors for Tommee Tippee nipples but they leaked a lot and when you turn it upside down, milk came out! Annoying. No issues with the Kiinde nipples. Love.Anyway these pouches have been an absolute pleasure to use. Kiinde upgraded the plastic at some point and now they are really nice and thick. May not seem like it matters but the older ones were very thin, and would sometimes leak when frozen ones were being thawed out in the refrigerator.I pump a lot... and I mean A LOT! Much more than the average. I could pump up to 30 oz a day (My boy drinks a lot and I work full time). The convenience of not having to pump into one thing and then switch is HUGE. I can't tell you how many times we've brought a bottle out in public and people will ask me "What on Earth is that? I've never seen such a thing!" and then when I explain they are blown away.I'm a huge advocate for this company and I do NOT work for them. I have told many nursing mommies that if they pump, they should be using the Kiinde system.NOTE: I know they say not to resume them, but we reused them a lot! They aren't expensive necessarily, but when you pump as much as I do, it really can add up (talking hundreds of dollars) if you used a new pouch every time. My rule of thumb was that if it was prior frozen milk, I would not resuse and would dispose of the bag. But if it was fresh milk or only refrigerated milk, I would reuse. You can buy a cheap bottle brush from Target that will slide inside the opening and twist it around to full clean out the entire pouch from the inside. This can save you a lot of bags and money, but I still wouldn't reuse them 10x, maybe 2-3x.I'm not sure why their nipples don't get more talk either. Everyone recommended the Tommee Tippee or the Dr Brown's and I have to say that these nipples are the best. No leaks at all. Wonderful flow for baby. We breastfeed beautifully in the morning and after work yet he downs his milk like a champ during the day. Really excellent!!TIP: If you are on the go and are taking a bottle with you, leave the blue cap ON. Do not travel with the nipple attached. It WILL leak. I have lost many pouches of milk from doing so. What we do is we put the pouch inside the white case and inside of a Tommee Tippee insulator and have the nipple placed separately inside.