It's nice that it looks so rapidly and reversably adjustable. So you can experiment very easily.
Tut the adjustments are nothing you couldn't do yourself with a few pennies of tape or foam, or maybe some sandpaper to remove thickness from your current insoles.
There are only 3 amounts of adjustment for each area - neutral, low and high. Feet vary so much that that can't be enough for everyone.
Also, tape or foam can also adjust fit - by placing material alongside your foot, or varying total thickness.
Of course, you could add tape or foam to R-Fit too - but if you are willing to experiment enough to do that, you might as well start with something cheaper than R-Fit, like a piece of carpet foam (closed cell if your feet get cold, open celled if your feet get hot and sweaty), or perhaps thin paper or cardboard if you need more space.
Another insole device that is sort of interesting is the Dr. Scholl's Footmapping Kiosks
(U.S. store locations here
.) While it too gives limited adjustment (it picks one of their commercial orthotics), it has the advantage of figuring out for you what you need. (As with R-Fit, you have to trim the orthotic to fit your current insole.) I think some people (especially some kids) feel pain, but lack the analytic skills to figure out where they need more or less support. And apparently some people, with conditions like "diabetic feet"
, don't feel pain, but still need adjustment to avoid health problems.