So I’m SDD? Got everything memorized. 
From my POV:
DDK usually have
- basic understanding of some heuristics (corners, sides, center)
- seen some joseki and tsumego
- have developed some sort of feeling of where they want to play
BUT - lack or quickly lose view of the entire board
- don’t have the shape intuition to reliably predict and therefore read sequences
- can’t tell if a move is forcing or not, i.e. they respond to every move (ain’t that right, @opuss
)
SDK
- know a great deal of heuristics
- have done quite a few tsumego
- have a lot of game experience, know common non-joseki sequences
- developed some idea of sente and gote
BUT - they’re still very easily manipulated into being greedy, envious, defensive
- can’t read very deeply and therefore
- don’t know how to handle unusual situations / when things usually considered bad are the ‘best’ option
DAN
- usually loads of game experience
- strong fighting shapes
- deep reading, usually recognize life&death in <8 moves right away, can read ~12 forced moves
- fairly independent of joseki because local outcomes are easy to read
- decent understanding of sente
- fairly well-developed global assessment
- know how to come back from a bad position, maybe due to experience with over-/trickplays
BUT - as a result of massive game experience, usually developed bad habits > unrefined style
- bad endgame - no one wants to practice it because it’s tedious
- lazy => stagnant, because improving takes massive amounts of effort at this point