Not too sure I can add much to what's been said but..
Cotswold will do a proper fitting if you ask them, tho the branch at Betws y Coed I think do so as a matter of course (there's a guy in his 50s there -or at least was there for some years - that has his own expedition footware-fitting company).
Ensure kicking your feet to the front (eg on the downhill ramp) that your toes don't touch the end, and walking up bending the shoe they're not impinging on toes etc - and if theyre too wide/big the leather bunches up in that area too. Istr the guy that fitted me also checked for where the boot flexed wrt my foot length. You can also use insoles to take up internal volume of needed (tho in my case didn't help)
In 30yrs ive had 2 pairs (hawkins, sadly the company's disappeared) and Brasher, both straightforward leather construction (tho the Brashers have a goretex liner), and I've worn them both pretty much non stop when on holiday since they're so comfortable. But the brashers have always given me a blister on the 2nd toe of each foot when doing a lot of steeper uphill since that's how the leather flexes. So the replacements - given trips to snowdonia - are some significantly taller/stiffer hanwags. But ive been keeping an eye out for some cheaper boots since theyre OTT for general/holiday/festival use, the brashers have worn smooth underneath and are cracking, tho not leaky yet I think. Hadn't seen the anatoms before but spotted them recently, wound up buying a pair of Q3 brairachs in my Cotswold local branch. (Again, ctc discount). Stiffer than the Brashers (hopefully no toe issues), havent got a high welt to lift, and not that much heavier - could have probably bought those instead of the hanwags if id seen them (tho more ankle support over boulder fields will be handy, so long as it doesn't stress my knees more !). Upper ankle lining is leather too which will probably be less sweaty with short socks - prev boots all leather lined.
Ymmv, but can't see much point of fabric over full leather - only time I've had wet feet was a day of pissing rain on snowdon last year, and everything was wet inside, prob from condensation. You get used to the weight IMO, and a goretex liner only lasts so long - probably not the 12-15 yrs a pair lasts me.
But try lots, and check sizes *around* what you think you need - different lasts exist even for the same manufacturer and a half size can make all the difference.