Have been Pioneer for years, started with a small Denon controller. I have the Prime 4 being delivered tomorrow to try out and considering this or the sc5000, x1800 option. Price is so good, hard not to plan on going with better mixer quality.
I will be doing mostly weddings but honestly setting up this setup is not much harder than setting up Prime 4. Not much on youtube so asking those of you here who own these.
I chose the option of the sc5000s and an x1800, I moved from a ddj-sx. I was a relatively early adopter, so at the time there wasn’t a prime 4.
I love the 5000’s and the mixer but if I had the decision to make today I would probably go with the prime 4. The reasons are
Value for money Portability for mobile gigs Denon seems to be putting energy snd effort into promoting and updating the Prime 4 above and ahead if the 5000s and x1800
The plus points for the 3 piece set up is that the players are great with the bigger jogwheels. Also the build quality seems very good!
Whatever you choose you’ll have fun! The software is poor on both setups and needs improving urgently though.
I prefer SC5000 (and X1800) because:
If one of the players should happen 2 go down, I can still do my job with the other one as there is 2 layers, until the first is back from repair.
I like big… Jogwheels 
When I went to Prime, there was no Prime 4. Now I have complete 4 deck prime setup (2x sc5000 and 2x sc5000M) with x1800. Prime4 looks good, but I would only use it at home. Full setup is a full setup. No shortcuts or compromises.
The Prime 4 is kinda like a mobile one man show meant for a mobile one man show.
The SC/M&X setup is is way more versatile in that you can plug external hardware and and if available synchronize with it. Send/Return, midi out, dual sound cards…
No deck beats the 5000M
I went with both but (for me) the Prime 4 has become my go-to. I miss the ‘big-ness and feel’ of the SC5000/X1800 setup during gigs but I don’t miss lugging it around and setting it up. 
And I love the option to run a playlist independently from the main mix, which is super handy during weddings.
send/return effects!
I am playing with the prime 4 and sc5000 tonight. I love the feel of the sc5000 but that screen of the prime 4 
Enjoy! It’s a really sweet setup and so far has been rock solid!! I wish the jog tension could be adjusted. Like big time. They feel weird. But everything else is super nice! Fingers crossed BPM stuff is cleared up with the new EP too!
Almost exact same story as me. I’d probably have gone Prime 4 first, but like to think I’d have the SCs and X1800 now, which I just love!!!
I opted for the big prime system because of the sc5000m and I am so glad that I did, I hung up my headphone about 20 years ago, now I wanted to do it just for fun. I tried the nexus 2000 and the sc5000 and a whole bunch of others, the sc5000m was the closest I felt to the old sl1200, I also love the bigger jog / platter. I know I could have gone the dvs route and used sl1200s but I love not needing a laptop.
This question is only really applicable to those who purchased one option or the other in the last few months, when both options were available.
Before the prime 4 was available, if you wants all the standalone features of prime, you could only get the 1800 and 5000
I bought over 18 months ago, to be free of laptops at gigs, so it was 1800 and 5000 or nothing.
I originally planned on buying a Prime 4 when it was announced but after countless delays I pulled the trigger on an sc+x1800 setup after using one at a party. I’ve been super pleased with that setup, and if they would every fix it so the beat grids support dynamic bpm tracks I’d say it’s near perfect for me. After a few months of gigging with that setup I decided to go ahead and pick up a Prime 4 which I use for corporate and smaller gigs, and break out the big rig for the higher paying gigs.
As I play a lot of weddings this setup allows me to use the Prime 4 for ceremony duties, while the big rig is already setup in the reception space. Plus in the event the big rig takes a dump it’s nice to have a completely compatible backup.
I facced this dilemma too, what swung it for me was years ago I had 2 x CDJ 2000 Nexus and a DJM2000 which I loved. I missed that big deck feeling I had on controlers I moved to after so I went for the SC5000’s/X1800 over the Prime 4, plus I was fed up of waiting on the Prime 4 pre order
Also the prime 4 was approx £1450 when I orderd but now its more like £1650 so its less of a saving than it was but I have to be honest if I was taking them out once a week or more I would probably go with the Prime 4 to take out and a set of SC5000/X1800 for the home studio 