My first attempt to convert from boots to trail shoes is a near failure. I'm interested in your thoughts as to what to do differently.
My wife, son, and I just completed the 100 Mile Wilderness wearing trail hikers over boots for the first time on an extended trip. Our feet are swollen and sore (with the exception of my son, who humped his mom's pack in addition to his own and had no adverse effects!). Our shoes reek, and despite repeated washings, our DryMax socks smell bad enough to wake the dead.
My wife is wearing La Sportiva Wildcats, and I'm wearing New Balance Leadvilles. Both have plenty of mesh.
We had worn these trail shoes on eight 12-19 mile training hikes in the White Mountains during the 3 months leading up to the 100 mile trip and didn't have any significant effects. Our feet were a bit tender as we learned not to step on sharp rocks–perfectly normal for transitioning to softer-soled shoes.
In the 100-Mile Wilderness, 40-50% of the trail is over rocks and roots, another 25% is through or skirting mud bogs/fording streams, and the remaining trail is awesome. Good trail was interspersed with crappy trail, but for the most part we're stepping on roots and sharp, glacial erratics. By the end of the day our feet are sore and swollen. We soaked our feet in cold streams/lakes at the end of most days and consumed many, many ibuprofen pills. A day and a half after completion, my feet are still very tender and swollen. I can imagine that if walking on good trail, the trail runners would be awesome, but are they really the best for this kind of rough, irregular trail?
I keep reading here about the value of simply hiking through the rivers and allowing the shoes to dry out on the trail. Due to the frequency of river fording and mud bogs, I was excited about not having to take the time to change into/out of water shoes. However, our shoes never really dried out. We pulled the insoles out each night, stored them under the tarp wings to keep them out of the rain, but due to high humidity I'm not sure they dried much at all during the night. Clothes that had been nearly dry while attached to the pack during the day were more damp in the morning when pulled from the drying string.
And our socks. We're wearing DryMax socks with the wicking outer layer and hydrophobic(?) inner layer. We pulled off socks during lunch breaks and at night, sleeping without socks. We had one to wear, one to carry. We washed the worn pair each night, wrung them out, and attached them to our pack to dry during the day. The "dry" pair we put on in the morning were mostly, but not quite dry. And the stink is amazing. It they weren't so expensive, I'd probably just burn them outright!
Questions:
1.) Are trail shoes better suited to smoother trails than what we experienced in the 100-Mile Wilderness?
2.) Are trail shoes better suited to drier climates with occasional river fording than wetter/humid climes with extensive crossings?
3.) Luckily we were able to treat hot spots before they became blisters, but I wonder how do you care for foot problems with perpetually wet shoes/socks?
4.) How much more acclimation is required than eight long day trips and 100 miles in 7.5 days, for a total of ~200+ miles in 3 months? I would've thought the feet would be far less tender by now.

