I don't know if my own experience might be helpful, but I have used Salomon, ASOLO and also Meindl (GTX Meran) boots on walks including Wainwright's C2C, Hadrian's Wall, Dalesway and West Highland Way, plus Yorkshire 3-peaks. I didn't get on well with any of them - ranging from leakage, sweating, rubbing, blisters and aches/pains no matter what I did. The most expensive (Meindl) were the most disappointing and troublesome. I have a wide-ish foot (probably an "E" fitting) and also slightly fallen arches, but not absolute pes planus (flat feet). I just couldn't get on with boots.
This year I swapped to trail runners and walking shoes. I completed the Hebridean Way in April with Merrell All Out Crush Tough Mudders - they are completely ventilated, but I found "managing" wet feet during the day and drying them at night was fine. My feet were much healthier, but I would advise that there is very little arch support - the inner sole is flat and for the type of terrain it would be better to have a bit more support for the foot. Width wise they were fine and overall I found them incredibly comfortable and light. I would unhesitatingly recommend these for well defined trails, but not the difficult tussocky conditions of sand dunes and peat bogs.
I happened upon a cheap deal for Merrell Chameleon 7 Slam shoes. They are wide fitting and very supportive of the arch. The sole is a bit firmer and I am quite sure I would have got on better with these on the Hebridean Way. They would have suited the terrain better. They are also fully ventilated but not as fully breathable as the Tough Mudders. Against my better judgement I wore the Cham 7 Slams pretty much "straight out of the box" to walk the Yorkshire 3-Peaks this year (a couple of weeks ago) and the Cham 7 Slams were utterly amazing - no issues whatsoever even though my son and I set a fast pace and completed in 8 hours 15 mins. These shoes were awsome and I would recommend for anyone with a slightly wider fitting who needs a bit more arch support and is able to manage wet feet with ventilated shoes (personally I wouldn't get the Goretex version - harder to dry them out).
I am also now testing some INOV-8 Trailroc 315s that are at a good price online from a number of retailers. Again, they are a trail runner and so have a flat inner sole (not much arch support), but they are ventilated, then have a firm-ish sole with terrific grip and they seem to suit my wider feet well. So far, so good and I think these will be my replacements for the Tough Mudders when they wear out. I would tend to use the Trailrocs for fast-and-light, mostly reasonably well defined pathways where the emphasis is on lightness, comfort and breathability at the expense of more support and weight.
I don't think I'll be going back to boots, even in colder conditions. My feet tend to stay warm and seem to get on well with wet, but ventilated walking in trail runners rather than hot, sweaty and confined conditions in boots. Trail runners seem to run true-to-size and I just use a thin cycling (short) sock from ALDI at about £5 for 2 pairs. These seem to work much better than thicker merino wool socks. Sometimes, however, I will wear an Otter waterproof for short periods, or the equivalent (and cheap) ALDI waterproof cycling socks that are sometimes available.
As I say, it's just a personal observation and opinion, but I hope it adds something to the discussion.
