(If you're not interested in the concept of an Advanced 5E, this thread isn't for you. Move along. Nothing to see here!)
I used "Advanced" just because AD&D did. That doesn't mean better, but it sounds better than "Crunchy 5E". The working title I have in mind is the '6th World System'.
If you ARE interested in the idea of an Advanced 5E - 5E with a bit more crunch - what features would you want to see in it?
Asking for a friend who is me who might make it.
I'd like to see 5e's version of Prestige classes, which I think is further development of the Factions concept from Adventurer's League. Make those five levels of reputation provide more benefit that currently, and develop the system to further explain how you can gain reputation and the obligations that come with it.
I'd like to see some of the stuff Matt Collville has been doing with the game, incorporated into it in a more formal way. Retainers, Followers, building your own Stronghold and Guild, etc..
I'd like to see a good full tactical combat optional ad-on, with some more melee oriented classes like the Warlord.
I'd like to see an optional Zero-level pre-hero rules.
I'd like to see more weapon rules, and more weapons. Lets see all those old polearms, and more differentiating between the weapons, with more than just damage dice they can do. Some more armor options might be nice as well.
I'd like to see an expansion of the exploration and social tier, with more rules for both.
I'd like to see some Epic level rules, with rules on becoming a demi-god.