The lid has very narrow corners that are extremely hard ...
931982
The lid has very narrow corners that are extremely hard to clean. The mug is a bit too wide for car cup holder, but it still gets stuck if you push hard enough.
2752860
The dividers come connected together and must be cut apart and trimmed.  Very tedious.  Once the dividers were installed the lid would not close without extraordinary effort.

EDIT: I took the dividers out and used a sharp razor knife to shave down the "nibs" (the excess plastic left when the dividers were cut apart) on the dividers.  The dividers fit much better and after this the lid worked well enough that my kid could close it.  I don't believe your average customer should be expected to do this to make a functional storage box.
2956996
Lid is very hard to close and kids forget to turn it to "off".
3821714
These are different from the Snapware at Costco and the lids don't snap on easily.
1471814
The lids are very hard to get off and on, but the product is sturdy enough for my purpose.
2463197
We hate this lid. I wanted to return it but we misplaced the bottle in our van and just found it and missed the return window apparently (Forza sports was the seller). Its almost impossible for me to get the lid open and it IS impossible for my 3.5 year old to open it. The button is extremely hard to push and once its open, its impossible to relatch.

DO NOT buy this lid. I wanted it to replace my daughters hard spout nalgene sippy lids. We will just stick with those. She only uses them for packed lunches anyway and drinks out of a regular cup the rest of the time.
1252023
These are nice containers.  The problem  I am having is it is difficult to snap the lids on and when and if I do get the lids on it is very difficult to get them open.
2774760
The lid is very hard to clean. There are nooks and crannies that are impossible to reach with a sponge or brush. I had to use q-tips to get up in there. Coffee, tea, and milk can build up in those areas and it can get gross. I wouldn't recommend this product.
2089988
It is a cute little bottle but the pink lid is very hard to open and close even for me ,so I know my 4 year old is going to be frustrated when she can't do it. I wish I would have read some of the reviews prior to purchase.
2546486
Sadly, the lids are very problematic as only the ones with the circles can snap shut. I would have returned them, but I work full time and go to grad school. I actually secure them with rubber bands when I pack my lunches.
4700178
Irregular shape so lids don't seal properly
1421262
I just received these and was immediately disappointed by how difficult it is to get the lids on. You have to have some hand strength to get the lids to snap in place. I was not able to while keeping the container flat on the counter, which will be very problematic if there are liquids in in the container. I do not recommend this product.
2461147
It's hard to give a review on this. The quality is nice, it works well with my convection range, it is absolutely the perfect size for a pot or rice or other small things. BUT my complaint is the lid. I'm OK with the glass, but the moisture and oil/butter collect under the rim. It is very hard to dry and keep clean. I have to take a paper towel and clean up under the rim to get rid of the moisture that collects there. Rather a big pain, but I will probably not look for a replacement as this particular size is hard to find in something other than a set. At least in convection cookware.
71823
Will barely accept one package of my favorite angel hair spaghetti, but the real beef is that lid fits so tightly that I had to use pliers to open it.  Made for cuts around the rim and now it can be opened by hand.
3560552
This lid must be screwed on very tightly or it leaks. And if for some reason you just want plain water for the day the fruit insert must still be attached for the lid to fit properly. The flip section on the lid is very hard to undo and I have to slam on it just to snap it shut, and this is not what makes it get a good seal. I can see the flip section of this lid breaking soon as sometime I have to pry it open because I just don't have the hand strength.
2976956
I received my Chef's Inspiration Fruit Infusion Pitcher  with Ice Core today. It is a very nice looking clear, thick acrylic pitcher. I like that the infuser core and the ice core both have threads that allow them to be securely attatched to the lid. The reason I gave this pitcher three stars is that I have concerns about the lid. The lid fits VERY snugly, in fact it is so difficult to get it on, I am afraid it might break it. To get the lid off I had to hold the pitcher under my arm and pry it off with my fingers. Also there is no way to "close" the lid. I received this product in exchange for my honest review.
4195769
This is a small stainless steel container with a small spoon that is kind of cute, but this review is primarily about the lid, which is difficult to use because it lacks any significant rim on the underside to keep to in place and has a tiny, tiny knob on top which is extremely difficult to grasp.  These faults render it less than useful for its stated purpose.