This is well after the question was asked so by now the OP has probably either kept the XV-5080 or they didn't. But as a FWIW I'll be keeping my XV-5080. That gives me ability to keep and use my favorite SR-JV's and have four permanent SRX's PLUS choice of SN's or more SRX's or mixture of both (up to four anyway) using I7.
I will be getting an I7 this spring, another few months. As mentioned, I already own an XV-5080, it is fully SR-JV and SRX populated. I also currently own a Fantom XR, with the sampling add-on installed, that is also fully populated with SRX boards.
Sorry but there are a FEW, yes it is truly just a handful of SR-JV "sounds," beyond the FX card, that I use that didn't make it across, either at all or as expected, to corresponding SRX. Additionally, I've never been real partial to the Fantom XR - it's too "sterile, too "clean," too digital sounding (too "pop") hard for me to describe but the Fantom is, to me, the antitheses of "warm" and real.
Not to mention the XR is not nearly as easy to navigate as the XV-5080. Since I bought the XR I now only use it as an SRX expansion unit.
When I get my I7 I will be getting rid of the Fantom XR and some TBD number of SRX cards but keeping the XV-5080 and all my SR-JV cards.
The hard decision will be which SRX's I keep permanently in 5080, and maybe a few others "just becasue."