The "ranger" might be fine if you want something bulky hanging off your camera and need remote control. But the Eye-Fi card is simple and effortless way of getting images to a phone or tablet. I use mine in the studio or location to show clients a "polaroid" of what I'm shooting. People tend to be amazed at how I can wirelessly send images to the pad. Sometimes I do get flustered when images don't show up right away on the pad. But the latest iteration of the Eye-Fi software seems to work much better in that regard.
Like Bernard, I keep the RAW files on the card, and only send the smallest possible j-peg over to the pad. Not all situations merit pad reviews, because it can really slow down the shooting experience. But it's a great way to check focus, exposure, and composition with a good sized image. I found the Nexus 7 pad 2 years ago to be the ideal size for this purpose.