I believe the novella is the perfect form of prose fiction. It is the beautiful daughter of a rambling, bloated ill-shaven giant (but a giant who's a genius on his best days).
Writing an informative yet compact thriller is a lot like making maple sugar candy. You have to tap hundreds of trees - boil vats and vats of raw sap - evaporate the water - and keep boiling until you've distilled a tiny nugget that encapsulates the essence.
Short stories are my favorite art form. A good one is compact and complete, a telling little slice of life, capturing a moment in time that - for the character - defines her, changes her, is the tipping point for all that will follow.
'Dune' was like a giant machine, and it was hard to keep track of all the pieces, but 'Blue Velvet' was a very sleek, compact little experience.
It is not a great Xerxes army of words, but a compact Greek ten thousand that march safely down to posterity.
My favorite form is the short story. From an aesthetics stand point you really have to pare down to the bone. You can't write a throw-away scene.
I write novellas because I don't like loose sprawling prose.
I write short, my words tight to the thread of the narrative.