Cotic Soul does seem to be the most appropriate in my opinion, owners say it has a lovely supple ride which helps with the ‘all day’ part of the OP’s requirements….hardcore?….it takes 140mm forks, how much more than that do you need?….any more and you need to go full suspension in my opinion.
Granted its not as slack as some other suggestions on here but do we all really need 65 degree head angles and bikes that ride like Choppers?
I’d also say research the build and find some reviews before purchasing….accepted wisdom is that steel is comfortable, aluminium is harsh and titanium is perfect….problem is titanium is a bugger to work with and there seems to be loads of failures reported on this forum with titanium framed bikes.
Aluminium can produce a nice flexy, springy, steel-like ride if done properly….the seat and chainstays on my aluminium Kona are beautifully narrow and the ride is superb….likewise there are some seriously hardcore steel bikes with virtually no give in them whatsoever and will feel like you’re riding a pneumatic drill all day.
Browse the CRC site, they are virtually giving frames away at the moment….find one you like (or priced right) then visit the manufacturers website to check the angles etc…its what i did with the Kona and things have worked out better than i’d hoped….i would post a pic in the ‘Beautiful Hardtails’ thread but its not niche or single speed and only has 100mm forks so would only get mocked by the STW massive!