1:06 p.m. on February 3, 2013 (EST)
A possible long term affect of too snug a toe box (also from over tightened fabric hiking boots/shoes) is an irritation of the nerve sheaths passing between toes causing scarring. Morton's Neuroma can be very painful and debilitating. I had mine surgically removed and a long consult from the doc.
You can tell when you have enough toe space (the doc says the toes should be able to play the piano in there) when the boots are the most comfortable foot covers you own.
Down hill travel can cause the fabled "Black Toe" when the toe and nail impact the front of the boot. If the boot is long enough and able to be snugged well around the arch so the foot does creep forward, that problem goes away. Sometimes a heel lift helps to move the foot up and back some. But that gives other gait problems too.
Too much over size is not good for your feet either. You need to find that boot that fits YOUR foot.
I had boots fitted at an REI (Pasadena CA) by an employee who had gone through their boot fitting program. Other outfitters go through the same program. I had gone to the store and picked out a boot that I had researched and wanted - it looked 'manly' too.
After chatting about the kinds of hiking I liked and how rough the areas I sometimes went to and weather and season and , and, she sized my feet with a Bannock - barefoot (over a plastic bag). First sitting down then standing up, then putting weight on one foot and then the other and rocking back and forth. Put on the boots and she laced them up, poked a couple of places where she thought the boot would rub. Then I was off for 20 mins of continued shopping (there is method in their madness) walking around the store and kicking the boots. Upon return she poked the same spots and others and asked if I could feel pressure there. She said I didn't want that boot maker's products and came back with two other styles
She had me put each set on and then kneaded the boot putting it back on (with socks) and poking again. We decided on a pair of boots by a method very much like going for a new optical glass prescription. "is it better that way or this way?"
Another 20 min trudge around the store - I did find something I hadn't yet bought and probably didn't need.
On the return she looked at my bare feet looking for more or less color in the skin. Flipped the boots and socks back on and poked and pushed, putting bitd of Scotch tape on the boots to mark pressure points. Off with the boots and she started working them on a booter's anvil. A long 'S' shaped piece of steel anchored to a large block of wood. From the inside, she would heavily massage and with a mallet pound the the spots she had tape on, putting some sort of liquid to help reform the leather.
Back on with the boots then one more time on the anvil.
A bit over an hour after coming into the store, I left with a size and style I had not even considered or thought appropriate. And with a promise to come back for more boot massaging if needed. she spent maybe portions of 20 mins with me making sure I got what I paid for. At other times I've spent a lot more time with sales people who just fetched and returned boots from an seemingly endless supply in the back.
From the start, there have been no hot spots, no scrunched toes, no sore feet and I put them on to walk around the house in when I come home from standing on street shoes a lot.
Oh, and the plantar facsiitis is gone too.
They fit like a glove...with a slight heel lift and insoles. It would be nice if these were to be the last boots I ever own.