I see a significant difference between radio buttons and the proposed solution. The change of state with radio buttons require a simple pointing and click. While with the sliding frame, a pointing and a constrained sliding operation is required.
When using a mouse the radio button is the most simple and efficient widget. But when using touch screens, the sliding frame seems a better solution because it avoids accidental state change, while still being a natural and intuitive operation to do with the finger.
So I would say that for touch screen devices (especially phones) the proposed solution is excellent and better than radio buttons.
That's totally a good point. Following this idea, in touchscreen devices there should be only one widget for both radio-button and checkboxes (which can be represented as boolean sliders)
When using a mouse the radio button is the most simple and efficient widget. But when using touch screens, the sliding frame seems a better solution because it avoids accidental state change, while still being a natural and intuitive operation to do with the finger.
So I would say that for touch screen devices (especially phones) the proposed solution is excellent and better than radio buttons.