I can see what you like from Dark Souls' take on level design but I'd rather the really unique and intense variety that Demon's Souls gave.
There's nothing like the immensity and claustrophobia of Stonefang Tunnels. We don't really get the long and daunting trek all across the King's Path of Boletaria. Latria is still unrivaled in its horror (THAT FUCKING HEART BEAT). We don't get the incredibly unique and quirky bosses of Demon's either. People call out Dark Souls 2 bosses all the time but I felt *that* about the Dark Souls 1 bosses. Demon's Souls has fewer sure but each are insanely unique aside from *one* and even then that specific boss is at the very end of the most oppressive and difficult level in the game. We've yet to get another oppressive and monstrous boss like Storm King with that crazy sound design blowing out your speakers.
edit: It's telling when the level people remember the most from Dark Souls is the one that is specifically detached and isolated so that it doesn't have to "fit" with the rest of the world.
I get what you're saying and it's a matter of taste, but for me nothing beats some of the moments that came from the connected feeling of DS1. Finally getting down to the Tomb of the Giants and the realization of 'holy shit this has been under my feet this entire time'. Getting to the end and being able to envision your trip from the Undead Parish all the way down to Lost Izalith. Nothing feels like that. It's such a real feeling world because of tis connectivity.
It also leads to moments of just wandering into a boss fight, something you can't really replicate in discrete levels. One of my favorite moments in probably all gaming happened because of that. Your wandering down the side of a mountain and you see this little forest offset. Wandering into it you all of a sudden see this giant stream of water as you agro a giant boss and in the distance you see this massive Hydra coming out of a lake. Nothing really else in gaming has felt like that. It's this mix of terror and excitement that only Dark Souls can really bring and it would've been lessened a ton if the world was disconnected with hubs.