They are definitely waterproof, once the foot gets used to them, quite comfortable although a bit heavy. They don't slip, as for whether they are sturdy, I will get back in 5-6 months

I wear size 43 in all types of shoes.
In these particular ones, size 43 was bigger.
In the end, I got size 42 and it's perfect.

You get what you pay for. I didn't enjoy these particular ones at all. They are not suitable for walking (warehouse worker) plus they can't withstand acids. Wear and tear comes from unexpected places. Of course, this specific company produces fantastic clothing and footwear products, but they also come with a corresponding cost. My opinion is that no one should underestimate the cost, especially for shoes that will be worn for 8 hours or more.

Just got them, I wear size 43 in sports shoes and I got size 42 in these. Fits me perfectly. First impression is very good, warm and comfortable. I will come back with comments in 1-2 months regarding quality and durability.. looks good though!
Update after 2 years of daily use (6/7 days a week, at least 7 hours each day), they just broke now. Completely satisfied, my feet haven't hurt at all. Now I will buy the same ones again!
update 3/4/24 I have also bought the second pair now and I am already using it! Excellent. Also, I will add that they don't smell.

It is a larger fit, so prefer to take a size smaller than what you usually wear. Perfect, I have had them for 3 years now and they have simply faded at the front of the toe. They are waterproof and do not slip easily. I will definitely buy the same ones a second time.