Here is the MBP specs I'm looking at

Originally released May 2015
15.4-inch (diagonal) Retina display; 2880-by-1800 resolution at 220 pixels per inch
16GB of 1600MHz DDR3L onboard memory
256GB PCIe-based flash storage1
720p FaceTime HD Camera
Intel Iris Pro Graphics

15.4-inch MacBook Pro 2.2GHz Quad-core Intel i7 with Retina Display

Yes, the 2015 MBPr 15" is the current king of the hill as far as Serato goes, unless you use Serato on a studio rig with a maxed iMac 27" or Mac Pro.

I'd even say that you can get comparable performance from the 2012 15"MBPr all the way up to the 2014 MBPr for well under the cost of the Mid 2015 and especially the Late 2016. They all Benchmark within arms length of one another.

There all 16GB w/SSD's, the real advancement is the Graphics and SSD throughput which jumped in 2015 and again in 2016, but I challenge anyone to tell the difference in loading a file using a SATA SSD vs. a PCIe Blade SSD and Metal Graphics make no difference in Serato.

at OP

The new Mac you are buying doesn't have a dedicated gpu which is not ideal for video djing

If you are planning to use Serato Video, you should consider either looking for the 2012-2015 15" MacBook pro with the 2gb video card.

The MBP spec you listed is more than capable for Serato DJ and audio.

You will need a license for the 4000. The SL3 has its own licence. You can buy the standalone licence Serato DJ licence which will let you use any upgrade ready controller.

Good call, I didn't think of the GPU factor with SDJ Video. I think the Dedicated AMD R9 GPU option is available for 2.5GHZ and 2.8GHZ models, at least for the 2015. I have the 2.5GHZ. I wonder if the GPU is utilized for waveforms and screen updates/sec?

Hey man any 15" 2012 or above MacBook Pro w/dedicated graphics card should be fine. For example I run a 15" mid 2014 mbp w/16 gigs ram and nvidia graphics card that is a beast. I'm taking 10-15% CPU with SDJ/SV,ME. You don't need the latest and greatest model mac a 2012, 13, 14 is just as good. Good luck

talking*

For a full Serato Suite with all the expansions, the Late 2013 15" i7 2.6GHZ w/2GB Geforce GT750m is an absolute steal. They were the first MB's to have 2GB GPU Cards, and nVidia cards are more widely supported among heavy 3D Animation software than my AMD based 2015. You could literally create video Animation using stuff like Houdini, Worldmachine, 3DCoat, Daz3D, Fusion360, Moi3D, Maya, etc, then encode them to your music library. it would run ROCK SOLID start to finish during every step.

Thanks everyone for all your input. I went ahead and made the purchase. I went to OWC and picked up the following eshop.macsales.com
Apple 15-inch MacBook Pro with Retina display:
16GB Memory | 1.0TB Storage
2.8GHz Intel Core i7 Processor
MGXC2CT/A (Mid 2014)
Ready for macOS Sierra 10.12
Like New | Factory Sealed Apple Refurbished
16GB on board RAM
Storage: 1.0TB Flash Storage
Two Thunderbolt 2 ports
15.4-inch LED-backlit Retina 2880 x 1800 display
NVIDIA GeForce GT 750M and Intel Iris Pro 5200
Mini DisplayPort via Thunderbolt digital video output for additional displays
Pre-loaded with Apple OS X 10.9.5
(Supported by Apple for up to macOS Sierra 10.12)

Also picked up the Denon MC4000

I purchased the VSL a few years back and don't use it really so it for gigs anymore. So the video card didn't factor in to much.

I am pretty happy so far with the purchase.

The Macbook has OS X Yosemite installed and looking through the forum and documents, I see Sierra is now fully supported with Serato DJ and Denon MC4000. I'm going to to ahead and update to Sierra.

I have not plugged in the MC4000 yet. I did plug in my SL3 box and the licence picked up right away for SL3. I was under the assumption that if you owned a piece of hardware with a licence like SL3, that all hardware products would be licenced. A little bummed about that it isn't universal but they did send me a promo code for half off so I'm very grateful.

I have my VSL licence key on my 2010 macbook pro, How do I go about transferring that over to my new macbook?

I have used that hell out of my macbook 2010 for 7 flawless years of DJing. I have had zero dropouts or issues. I am so nervous to be making any kind of changes but also extremely excited to finally get to update my Serato to SDJ from SSL and have access to working with a controller when needed. Crossing fingers

one thing you can always do is to partition the HD for dual booting.

I keep a 50gb Yosemite partition on my hard drive.

I use Sierra mainly but I've had issues on a couple of clubs where provided gear wouldn't work or misbehave with the latest OS.

a quick reboot into Yosemite saved the day.

Caveat : My library is on external and all my crates move with the library.

congratulations on the new macbook pro and welcome to Serato DJ.

Thing is going to run rock solid for you.

Are you going to run Ableton Live 9 as well?

I also keep my hard drive external, I gave Serato DJ a good hard workout in practice last night without a hiccup using Denon MC4000. Basically ran everything I could including SLV flawlessly.

I am a little intimidated by SDJ's UI but it'll just take some getting use to with practice and play.

I have a large gig tomorrow where I will be using my old 2010 MBP and SL3. Saturday I am doing a chill recording gig without a dance floor and will try out the new MBP with the MC4000. I will mainly be using the new MBP with SL3 in clubs with CDJ's and will break out the MC4000 for smaller venue and travel gigs where I'm not always sure what I'm walking into. I can't wait to use the new MPB for all gigs, but until I get a good 20 hours practice DJing on it I'm sticking with my 2010 on SSL.

I've never used Ableton live, I'm generally a track select and EQ kind of DJ. I am looking forward to lightly using more effect and samples on the MC4000.

At some point in I would love to open up my FL Studio and get some production happening. I will definitely be taking advantage of my MBP for that.

Thanks again for everyone's input. I have loved our Serato community since day one.