In my opinion all styles are demanding when going for perfection Milonguero no more than Nuevo, and vice versa. I would say that the basic intention of Tango Nuevo was to go where no on was before, to dance like no one danced before, to try something new. Since Nuevo isn’t around that long, it’s much harder to draw the line what actually is Nuevo and what isn’t. Some Nuevo elements sneak into other styles. Not only into Show Tango but even into the Milonguero style. (Look at the YT videos of Oscar Casas) While I like to play around with Nuevo ideas, there seems to be little use for them. For the Milonga they are to big and for shows many are to boring.
Right now, Nuevo has the attraction of being new. It will be interesting how much of it will be around in 20 years or more. Eager to “develop” Tango, many Nuevo protagonist god rid of all tango cliches: no evening wear, no traditional music, no close embrace, no traditional rolls of gender, no absolute determination of timing and lead by the man, no figures you can dance when your 80, no high heels, no fancy stage shows, neither pattern to dance in tight space. All those factors which usually draw people into tango. To me the end product appears to be the crystal clear, sugar free, decaf, lemon flavored coke of dance. So maybe we witness the birth of a new dance, like the beginning of ballroom Tango 100 years ago. Pure Nuevo seems to be for people who like the Tango life style, but not the Tango.
Of all styles, tango nuevo seems to have the biggest attraction on rude dancers right now. Since there is little specific Nuevo tradition, there are no common rules on etiquette, which gives freedom but also the perfect excuse for you to pass off ruthlessness as the final peak in tango evolution.