Comfort

While the Nucleo is an all-around impressive boot, comfort is one category where it really shines. It is by far the most comfortable of the boots tested due to the padding all around the ankle and tongue. It is made of full nubuck leather, which provides immediate comfort right out of the box. Another common complaint among waterproof hiking boots is their lack of breathability. La Sportiva got around this problem by using Nano Cells, a polyurethane, fine mesh material, which allows air to circulate under the foot.

Support & Stability

Overall the Nucleo provides a lot of support and stability and is only beat by the Oboz Sawtooth. It uses compression molded EVA and TPU inserts that do a great job of providing the needed stability, even on tricky terrain like steep and rocky trails. The Nucleo is a high-cut boot that sits above the ankle to provide support without ever feeling restrictive thanks to its flexible leather material. The only downside is that the boot does feel a bit warm in hotter conditions.

Traction

The Nucleo features a Vibram Nano sole which grips well in many conditions. It provides great traction on wet, slippery surfaces or when scrambling over rocky terrain due to its aggressive tread and sticky Vibram rubber. It also uses a so-called Impact Brake System on the outside heel to cushion impact when hiking down steep hills.

Protection

In terms of durability the Nucleo is full nubuck leather which is highly resistant to abrasion and much more durable than the more commonly seen combination of mesh and synthetic uppers. After a few uses the boots did show more signs of wear, mostly due to their color which displays scuffs more prominently than a darker colored boot. However, since it doesn’t use any mesh and has a high cut, it provides a lot of protection from rocks and debris entering the boot. It also uses a Gore-Tex Surround lining that is fully waterproof and breathable, so it is great for hiking in warmer temperatures. On the other hand, this could prove to be a disadvantage if you’re primarily hiking in cooler conditions or navigating icy stream crossings (purely for heat loss, not because of any water ingress).

Weight

The Nucleo is middle of the pack in terms of actual weight compared to the other boots tested. The North Face Ultra Fastpack II and the Lowa Levante are both about 5 ounces lighter, but they sacrifice a lot to achieve that weight. The Nucleo still feels like a lightweight hiker which is impressive considering that it’s a high cut supportive boot.