Yes, I have one on my 1624-II. I can give you my observations and impressions, but in the end its value is going to depend on what you want to do with it and how and what you turn.
I have used mine a couple of times for turning, but it didn't really help that much for what I was doing. You can use the outrigger on small pieces that begin life between centers, which is how I was using it, but I found it was just easier to rotate the head stock part way and pull the banjo out. With the head rotated 90* and the outrigger set up there is a limited amount of space between the end of the spindle and the tool rest, and a chuck takes up a good bit of it. I could measure that for you if you want but as I recall with a chuck on the spindle there was barely room for a 3 1/2" block and the tool maneuver space was cramped. Certainly a 2" thick platter, would be very doable. But if you are looking at the outrigger option to turn a blank that's too big to start between centers you will, as Gary says, have to be on a face plate (I can't imagine any way you could create a secure chuck mount).
For a big blank if you are turning a blank that is a uniform square or circle I think you'll be fine. But if your desire is to turn an irregular lump of tree, or you didn't get the face plate in the center of your blank, the load is going to start out very unbalanced. I don't know for sure about the DVR XP, but based on my experience the 1624 on steel legs is too light to handle that load.
So if your goal is start out with a fairly round blank of uniform thickness on faceplate, I think the outrigger will work. If you have an unbalanced load or a thick piece on a chuck I think you are going to encounter limitations.