I think they both have their good & bad points in different ways & end up quite equal tbh.
For instance in DWTS;
I hate the over-marking of
everyone & gushing sychophantism

(esp Bruno who's obviously trying to "make friends & influence people").
I love the professionalism of the presenters.
I find the competetiveness of the majority of celebs a bit too much.
The camerawork is much better.
The singers/orchestra are better.
Too many adverts.
In SCD;
I'm afraid Bruce & Tess are a bit grating now & he's obviously not as quick on the ball as he used to be!
I don't like the obvious favouritism of the judges.
I find our celebs more down-to-earth & "likeable" as they don't appear to be over-competetive, (baring the odd one usually).
I prefer our costumes on the whole & music choices.
The camera work is pants they are still spinning around the faces while missing fancy footwork

.
This is my little old opinion of course

.