FIT:
I wear size 8 Width D/E and have a high arch.
I purchased size 9 and the fit with medium weight socks is good but with a light/medium weight combination there is not enough room in the toe box to easily wiggle my toes and that means circulation issues are a good bet on a long or all-day ride.

The speed lace string system makes it easy to secure the shoes even with gloves on and the string tab stows with out discomfort under the zipped upper.

Even with my high arch zipping the upper is easy and because the zipper is not holding the shoe on your foot, it is only keeping the elements out, it does not squeeze my foot and restrict circulation.

I have not yet ridden in wet conditions but the upper is very effective at keeping cold air from penetrating into the shoe.

TEMPERATURE:
On a ride at 50°F - comfortably warm
At 38°F - comfortable no hints of chilly toes.
At 27°F - after 35 minutes toes slightly cool but not uncomfortable.

All rides were a 45min commute to work with one pair of medium weight socks.

WALKING:

Comfortable and easy much like wearing medium-topped hiking boots.

CLIPPING IN AND OUT:
I use older Time ATAC pedals and clipping in and out is fast and easy, while riding the shoes are secure.

RATING:
I gave the Fizik Arctica X5 five stars because the workmanship and material quality are excellent.
Putting the shoes on and taking them off is fast and easy. Most importantly they are warm into the 20s F. The Arctica X5 performs as promised.

WISH LIST:

Wider versions of the last for a larger toe box.

Los zapatos están bonitos pero tengo un inconveniente con la talla. Yo encargué 9 o 42 pero me entregaron una talla más chica me dieron 40 y no me entran. Es por eso lo regreso. Lo volvería a pedir pero en talla 42. Gracias

Fist I ordered the size 42 which amazon said was a size 11. I wear a size 11 in Adidas and Nike. My foot is on the narrow side. The 42s were very tight so I returned them and got 43.5. They fit like I think an 11 should fit but are still to tight for winter shoes. If you want to wear thicker socks then you need to go bigger. My feet aren't freezing anymore but they could be warmer if I had enough room to wear thicker socks with out it being so tight. Other than that I am very happy with them. My feet stay dry and are a lot warmer. If I ordered again, however, I would get at least a size 44.

I've been looking for the ideal winter waterproof cycling boot, tries the specialized boot which was not comfortable at all! Since I've been using Fizik road and gravel bike shoes for many years, I thought to give these boots a try. They are comfortable, exact size as my other shoes with plenty of room for my merino wool socks. I thought about sizing up from 41.5 to 42 both then the show would be too big for me to keep proper fit while cleated. Overall great investment!

They have been great in the cooler weather and have done well to reduce road spray and wind penetration...warm toes are great. Make sure to lap a water resistant layer over the top in rain for better effect.

The boot size I ordered fit as expected.

The boot could benefit with a 2 to 5 mm shift off the center cleat mount to accommodate wider footed people; the instep side is uncomfortably close to the crank.

I do not recommended for extended walking as the boot is designed with reduced articulation at ankle.