The Denon is a much more advanced player than the CDJ1000, feature-wise, but still the Pio wins with me (by a slight margin) for being a solid, no frills, in-your-face top deck.
Not to raise old ghosts and debates about the spinning platter, Denon never seem to do away with the confusing interface design, and I (IMHO) felt the 5000 suffering the same layout and operation flaws found on all their more advanced players such as the 2100, 2600 and 9000.
Which wouldn't be a problem except for the short-minded jocks like me but is rather limiting to pretty much any DJ who don't own a deck and has enough time and patience to practice and find way thoughout the submenus and multi-functions... Those who won't also be able to pre-program, load and take full advantage of some advanced features, unless they take their players to clubs and gigs.
Thing is, real life DJing is just too dark, smokey, noisy and fast-paced for cramped surfaces, short pitches, tiny displays and overloaded submenus! Same is happening to those huge DIM car stereos, makers are moving out from micro buttons and commands cuz you have to focus on driving, such as the DJ must focus on the performance rather than the equipment!
That's just MHO though...