Hydration Biosensor vs Water Resistant Watch Model 8R500 - Men: which is safer?

Where these two actually differ

• We flag Polymer additive leaching (plasticizers, residual monomers), Electrical leachate from conductive coatings or adhesives, Inadequate biocompatibility testing disclosure and Sensor performance degradation and unknown failure byproducts on the Nix Biosensors and not on the TomTom.
• We flag Polymer case and band degradation and Bacterial or mold growth in seals and band on the TomTom and not on the Nix Biosensors.
• The Nix Biosensors is Biosensor electronics, likely silicone and/or polymer substrate with sensors where the TomTom is On watch case and band, which is most of the difference in these two grades.
• These two are level, close enough that price and fit should decide it rather than our grade.