Are you running monolights? If so, do you already have a 1200 wattsecond head? The Ranger's extra stop of power above the 600RX monolight could come in handy when working outdoors against ambient.
I've found that the Ranger fits nicely into a studio workflow despite being battery powered. Fewer cables, lots of capacity for hundreds of shots, fast recycle. It might surprise you and end up seeing regular use in your studio.
The Ranger might also be a bit lighter/more compact than the inverter/monolight combination.