All devices perform the basics: weight, body fat, Body Mass Index (BMI – a crude calculation based on your height and weight, only), and all scales have an “athlete mode”, which adapts to Athletes in Training – people engaged in a structured program designed to raise their performance in competitive events.

It’s at this point where the feature sets start to diverge.

Attention: The internal data of table “19” is corrupted!

The Aria offers the fewest functions: weight, body fat, and BMI. If you already own one of Fitbit’s other connected devices, the opportunity to integrate them via Web site and app may already make your decision clear. On the other hand, at a price point in between the other two entrants, aside from integration, brand awareness may influence sales more than actual value.

The iHealth scale offers the most functions with nine in all, all oriented toward measuring body composition. Withings follows close behind with eight total functions, including three unique (in this group) metrics: heart rate, ambient CO2 level and air temperature. Since heart rate is closely associated with fitness, it’s easy to understand why it might be included among the other features.

What’s not so clear is why environmental measures are taken – until examples like the air conditioning episode described earlier arise. Tripling of household CO2 levels just because the air conditioning is on is worth knowing. Follow up testing will occur once winter sets in here in New England.

The differences in what these products track suggests the question of what can be reliably tracked, how, and where remains open. Settling the question of the “right” feature set will be interesting.

Time for Personalization.

Quick links to buy at Amazon