As mentioned before, I took both pair to Ireland to walk the Kerry Way in August 2016. Honestly, I ended up using the 106's more because they are much more comfortable and fit my feet better because of the lacing. My best guess is maybe a 65-35 split with the 106's taking the biggest load of miles. That being said, I walked the 2nd longest hike in the 109 through a variety of conditions on the Irish countryside.
Using the Darn Tough sock and a combination of shoes, I had zero foot problems over the 100 odd miles of hiking between the Kerry Way, the towns and pubs. The Goretex did make my feet slightly damp from perspiration after 10 hours of hiking in 60 degree weather.
When we decided to hike the Grand Canyon in March 2017, down South Kaibab and up Bright Angel, I decided to only take the 109's. They handled like a champ on everything except the packed down slick snow near the top of each trail but in all fairness the 106's wouldn't have faired better.
I still like the 106's better.
At the end of the day, I still prefer the 106's as they are more comfortable, but as the 109's broke in I like them better than I did originally. They are still sloppier than the 106's in general.
Here is an Amazon link to the North Face 109 shoes. I do get a little compensation if you click and buy. It means I can buy more crap to review.
Check out my initial review
