It looks like a very high-quality shoe, but I give it 4 stars for the sizing guide.

To help others with their order, I will say the following:

My foot is 28.5cm long (relatively narrow). According to the guide, I should have gotten a size 44.5. However, I ordered a size 45.5 because I have another Under Armour shoe in size 45.5 and it fits me perfectly.
In this shoe, even the 45.5 is tight for me. I believe size 46 would be just fine.
1.5 sizes larger than what the guide says......

Edit: I climbed Mount Olympus with these shoes. They are indeed very high-quality, especially for this type of activity. The sizing issue doesn't change anything I mentioned before. Fortunately, even though they were quite tight, they didn't hurt me. I still believe that size 46 would have been the perfect fit.

Very good shoe. The only thing I hadn't taken into account is that it doesn't "breathe" well, since it is waterproof and in the summer my feet sweat a lot. Other than that, it is perfect.

Beautiful waterproof shoe. It slips quite a bit in water and hits my left toe on the top part. It has a narrow fit. Not very comfortable. I only have them for walking. I wear size 45 and got size 46 and they are still tight. I think Asics and Nike are better.

Very good... But compared to the size you wear, you need a half size larger. They hurt the foot. And you can't say they're light either...

Well, it's good, comfortable, but the fabric on the heel tore, which is annoying after 6 months