Have you tried the range of boots from Ecco? Very comfy!
Ecco are fabulous. Their leatherwork is exemplary, and comfort is superb. For a good 12-18 months after purchase, you bless the day you found them every time you put them on. It's almost a religious experience.
The secret is the soles, which I believe are made using blow-moulded foamed solvent-based material, using an extremely clever process whereby the layer of sole closest to your foot (ie, uppermost) contains the most bubbles, and relative density of the material increases (with decreasing squishyness) the closer you get to the outer surface of the sole.
This is genius, because it effectively forms a progressive-rate spring, which is extremely beneficial in context. The outer (pavement-facing) surface of the sole is solid, and bubble-free.
Then one day you find that they're making an odd "schhhtk" noise when you walk across carpet, and they begin to feel as if you've trodden in two massive pats of discarded chewing gum. Examining them, you find that the soles are somehow sticky, and if probed, will start to crumble and fall apart in your hands.
"Great Scott!" you exclaim, "I've not hammered them that much". And you haven't -- not that it would have made any difference, as the problem is time-based, rather than wear-based. During the year of the Hale Bop comet (can't remember when that was, but it was certainly that year), I found a pair of Ecco boots that I instantly loved. They were pigskin suede, lined with calf leather with Gore-Tex as an interlining, and they had my favourite lace layout with two pairs of hooks (rather than eyelets) as the uppermost lacing points.
They were available at an excellent price, and thinking that I'd find it hard to replace them, I bought two pairs (the second pair was oxblood leather, but otherwise the same). With great discipline, I stored the second pair unworn ("their time will come").
18 months later, the soles on the first pair started to disintegrate. The rest of the boots (uppers and linings) were absolutely fine -- no problems whatever. I took them to a cobbler, who of course told me there was nothing to be done, because the entire moulded unit had effectively failed. He could grind off flush, and attempt to glue a new outer surface in place, but this would effectively be like gluing something to the inside of a Wispa bar -- it wouldn't stay glued because all the bubbly cavities meant that the contact area would be impossibly small, and of course the new outer surface wouldn't stretch or deform in the same way as the substrate when walking, so would be subject to constant shear forces.
I went home in despair, and wrote to Ecco -- surely they'd want to support their product, and make good what was clearly some sort of error in the production process. And I cheered up when I remembered that I still had the other pair stored (unused and still boxed in tissue after initial trying on).
I unpacked them, and recoiled in horror when I had difficulty peeling the tissue off the soles. My spare (unused) pair had degraded themselves at precisely the same rate as the first pair.
To this day, I've never heard anything from Ecco on this -- they just ignore it. But around this time, a friend who was clearing out his wardrobe found a pair of Ecco shoes which he'd bought in a hurry and had never fitted him well -- they were in good condition and fitted me fine. I wore these on and off for about 6 months, and they too then started to dissolve.
It turns out I wasn't alone -- there are literally hundreds of other buyers with the same problem -- just searching on "ecco shoes soles disintegrate" will give some idea of the scale of the problem. Ecco claim to have fixed the issue, and some buyers have apparently received vouchers for new replacements -- although I've never even had an acknowledgement. Consequently, initially loveable though they may be, I will never again buy Ecco shoes.
Red Wings are mostly brilliant -- but some of their boots are generic Chinese-made items, so you need to ensure that you're buying an Idaho-made model, which are properly low-tech (Goodyear welted) and therefore properly repairable by a proper cobbler, meaning that you'll get the life out of the uppers.
RM Williams also deserve a mention. They're not initially 'comfy' and require some wearing-in to get anywhere near that, but they're uncompromisingly beautifully constructed, with very good cut selection for long life. Their only real problem (I find) is that being built for Australia, they're really cold here, so you need to allow for a thicker sock in the sizing. They're also massively cheaper in Australia (worth getting someone to send you some as a 'gift'). I bought 'Gardeners' on holiday there for about 75 quid, and this included a free shirt (which is to the same standard). Can't argue with that.
Edit: Just read the rest of the thread, and Matthew, I really must complement you on (in this case) your impeccable taste and insight. Your Foremans (Foremen?) are terrific. It's really useful to see how a particular design ages, and Red Wings just get nicer.