Hi Steve, welcome to the forums. Enjoy your time here.
My personal experience with the VMS4(.1) isn’t all that. The MC6000 is a solid choice for a mobile DJ, but you need to know your way around it to be able to cope with the cramped space. Everything is really close together.
If you search the forums for advice on starter controllers, you will find a baseline there. In short:
1) Determine your (desired) workflow. Should be a little easier for you as you are an experienced DJ, but inexperienced when it comes to Digital DJ-ing.
2) Find the software that most closely (100% match is Utopia) your workflow.
3) Set a budget.
4) Pick the 2 (max. 3) controllers that fit both your workflow and your software.
5) Get some hands on experience on your shortlist controllers and pick one.
I would not spring for a high end controller at the stage you are at now. Better to get a true starter controller, even used if you can find one (Numark Mixtrack Pro 1 through 3, Denon MC2000, Pioneer DDJ-SB (1 and 2) and Reloop Beatmix 2).
My suggestion would be to get the How To Digital DJ Fast course over on the main site. It is completely money back guaranteed, so if you find it did not offer you enough you can get your money back. A no-risk proposition.
It will take you, quickly, through all the basic (including, clearly, some stuff you already know as an experienced DJ) as they pertain to DIGITAL DJ-ing. It will help you set up a practicing regime without bothering with trial and error establishing of best practices.
You will very soon get the hang of it, get to know your software well, bring your collection in order, figure out what does what and learn some new transition techniques to help you into the 21st century :-). You will also start to finetune your workflow to fit the digital realm. So by the time the starter controller will have taught you all it can and you have determined that your choice of software stands and you are ready to upgrade, you will hit the market place with a way better understanding of what it is you want/need. So easier to stand up to those hotshot sales guys LOL.
As far as high-end controllers for mobile DJs go, Denon just launched the MCX8000 and, in my very humble opinion, it is THE mobile DJ controller currently out there.
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