I agree with you, it would be a nice idea… unfortunately I foresee it would just attract massive amounts of trolling for not being direct drive like the ‘industry standard’.
The DDJ-S7 is a heavy beast isn’t it, add two more channels and all the other Prime 4 features and it becomes a monster imo.
Yeah same, Prime 2 in Magma case, old Technics record bag with cables and sub mixer etc, Proel monitor speaker and im ready to roll, can carry all 3 at once and manoeuvre through busy bars to the DJ booth.
Folks would always have opinions…its a given.
For example despite opinions about cost, they still buy the Pio stuff eh he.
Yeah fair point:)
Booh, direct drive >>>> belt drive 
My first reaction is “nah, I want to step away from the laptop, no need for controllers!”, but whatever floats your boat… I do wonder however why I don’t like controllers in the first place, and the answer is that it was always a hassle to make mappings, and drag around your own gear. And sadly, I am still dragging my own gear around (Denon SC6000’s this time…) since CDs became obsolete.
So in retrospect, IMHO the biggest innovation anybody could make is a standardized USB stick format, just like standardized audio CDs and vinyl records. That way we can just play at whatever hardware a club offers us… It would make the whole “what hardware to you want” pretty moot.
Ofcourse, nobody is going to give their format’s definitions and API’s to the competition for free. But if you ask me if I would pay a fee for using that format? Well, if it means the same freedom I had with CDs and vinyl, but with the weight of a USB stick? I would seriously consider to say yes! On the other hand, a common format doesn’t tie club owners to Pioneer anymore: If for example Denon would start to allow other competing brands to use their database format, they would be much stronger together to smoke Pioneer out of it’s position, and force them to use that common format too…
I know there are a few tools trying to sync your libraries for multiple formats, but that is still a big hassle where you have to spend time to the syncing process, and where syncing errors can occur. It’s a totally different thing than one universal format!
It ain’t that bad 
Im sure it can be compensated for in software, but belt drives have an insane amount of wow/flutter and pitch inconsistencies that vary depending on environment. There is also a good amount of motor control lag. Fun for scratching, but terrible for mixing.
There are only two brands out there right know for a real club environment. Pioneer or Denon.
Denon allready decided to integrate rekordbox sticks with the ability to use cue points. However pioneer created extra a new protocol to prevent Denon from doing that. And pioneer will never give the ability to use Denon sticks. Not in this life. The whole point of Pioneer is to prevent users from switching to other brands.
I haven’t had to make any custom mappings for any of my serato gear. The option to make customized mappings exists but it’s not necessary at all.