If you take into account the expected costs for the CV1 handsets, there's virtually nothing in it.
The pros and cons appear to be:
- CV1 is generally considered to have slightly better visuals and SDE
- CV1 is supposedly lighter and move comfortable
- Vive has roomspace and is better enabled for it. So for example, it also has a significantly longer connection cable, which is rather useful when you're moving around
- Vive has handsets right now. CV1 to be launched
- CV1 is cheaper if you don't need the handsets. I play mainly sims (ED, ACS and DCS). So the handsets really don't appeal as I already have a HOTAS. Saves me some of the cost for my HOTAS
- CV1 looks like it's getting something fairly similar to roomspace, but I'd be surprised if it's quite as good, as the Vive was designed for it and for example, has another sensor camera
- Vive is directly linked to Steam. That "might" influence compatibility with games over time. Oculus has facebook backing, though I can't see that making much difference
Above all, do you have the physical space and want Roomspace?
Personally I have a very small physical location, so the decision was dead easy for me.