I used a pair of Brasher Hillmasters for many years, but they gradually became uncomfortable, so I tried various other types, e.g. Mendl, Salomon, etc. without success. Then I began to realise that the size 10.5 I'd been wearing for all my adult walking life had become too small as a result of creeping arthritis. Upping the size to 12, wide fitting, helped a lot, but I increasingly struggled to walk for any great distance in comfort. I bought some Altbergs, but they moved around too much on my feet. In the end, I abandoned the big, heavy, leather "Alp-cruncher" style of boot, & also looked out for boots without a pronounced heel, more of a curved sole giving a rocker action. This was suggested to me by an orthotist, and was the best move I ever made in achieving comfort.
Contrary to a previous poster, the most comfortable boots I've found to date is a pair of Adidas Goretex Terrex hiking shoes. They really are superb - great cushioning, light, good ankle support (more of a boot than shoe), very wide, and with an excellent "Continental" sole that grips extremely well on slippery rock but doesn't get clogged up. I've given up trying boots in shoeshops - you can never judge how good they're going to be when used in anger, & I've had more success in buying on-line. I've also bought a pair of ON Cloudrock walking boots, which are very light and comfortable. My only issue is that despite what they advertise, they're not very waterproof (a good drenching in Nikwax cured that though) & their cleated soles pick up stones.