I bought some Nuno sneakers and decided to get some shoe trees with them.
The trees are gorgeous and practical. The cedar wood is aromatic and the metal pieces, including the springs, are sturdy. The springs fill my Nunos superbly even though they don't really seem to be lasted to the shoes. This is actually a blessing for the shoe trees as it means they fit a wider range of shoes. I would like for the heel of the trees to be taller though; the top of my sneaker's seem more creased than they could be. The price seems fair, specially for someone in Europe like me where shoe trees are more expensive and rare.
In conclusion, I decided to buy 2 more pairs for my other shoes. Can't recommend these enough.
Pro Tip: You can adjust the amount of expanding the toe box can do by tightening of loosening the middle screw of the toe box.