Oral-B iO3 currently has an unusually aggressive $59.99 direct sale price and a very clear visible pressure sensor. Sonicare 4100 uses a traditional elongated sonic head, includes pressure sensing, and Philips publishes a 14-day battery claim. Replacement-head economics depend heavily on pack size.
Side-by-side
| Oral-B iO3 | Sonicare 4100 | |
|---|---|---|
| Brush action | Round oscillating-rotating iO head with micro-vibrations | Sonic elongated head |
| Pressure feedback | Visible sensor | Built-in pressure sensor |
| Modes | 3 | Model-specific simpler control set |
| Battery claim | Long-lasting lithium-ion; no fixed duration on current page | 14 days on current Philips page |
| 2–3 head pack economics | $29.99 / 2 iO heads | $26.95 / 3 C2 heads benchmark |
What public users tend to split on
Public discussions frequently describe Oral-B's round head as giving a stronger “scrubbed” clean feeling, while Sonicare users often prefer the more traditional head shape and quieter sonic sensation. Those are subjective experiences, not proof that one cleans better for every user.
Our decision rule
If you strongly prefer one head style, buy that ecosystem. If you are neutral, compare current handle price plus three years of replacement heads. Consistent use dominates marginal feature differences.