We bought 8x of these for twin boys - All flip lids just fall off and we don't bother putting back, the base is so hard to screw on after washing with friction we need to put margarine in the thread every time as lubricant to make them click lock and lastly when the straw is pushed down it pulls down the attached little stopper and opens the breather hole that then dribbles everywhere...
Anyway, with all eight having same issues, not sure what is better bottle out there but these take a lot of work to maintain for us

Have purchased a few of these now. Doesn't leak at all, HOWEVER, you must squeeze the straw to activate the one-way valve near the top of the straw. I wonder if many of these negative reviews just didn't read the instructions (perhaps write this on the packaging rather than in tiny print in the instructions sheet).

Taking one star off as the straw is super easy for my son to chew through, and replacement straws are expensive to ship/impossible to find, so I end up buying more cups = huge wastage :( Would prefer if it came with a stronger, but still soft, silicone straw.

Not sure if I just got a dud, but it leaks everywhere out of the straw! My bub (7 months) shakes & tips her cup upside down at meal times & so much water comes out of the straw. She watches it dribble out onto her high chair & then plays with it.
Also, the 3 times I have taken it out of the house in her bag, it has leaked. Out of the straw. With the lid closed...I honestly don't recommend this product. Because of the leaking I've had & because I can't seem to find replacement straws. Gone to a B.box instead.

I bought 4 bottles - one in each colour - which was nice. Two out of four have been good - click lock into place and no leaks. One leaked however and I sought a refund. The other I find doesn't actually click lock into place and I have to screw the lid on very tightly so it doesn't leak.

I love the weighted straw, how easy it is to clean and that no water comes out if ripped upside down. I did have the problem of it leaking through my bag so this bottle is for home now. Not sure why this happens but it worked well at the start!

Loved the weighted straw are no mater how much they tip the bottle to drink the straw moves with it and they can still drink. Found though after a few months of constant daily use it does start to leak and it leaks all through bag and wets everything.

Great product, easy to clean, and my son loves to tip upside down and look at the weight inside, and it’s never leaked! Highly recommended, don’t bother with other brands