What I am discovering is that each wearable collects similar raw data and interprets it differently. What I mean is not that one is better than an another, rather, different parameter or criteria is used to inform the person. A simple example is how fitbit and MSB shows the same data. While HR is straight forward, things like sleep data, workout data are all presented differently in each respective app.
In another words, the tracking info is fragmented to say the least. I suppose that's one of the big reasons that apps like MS Health or Apple Health apps cannot present a whole integrated picture. myfitnesspal accepts input data in terms of weight (from smart scales), calories burned and steps but its very one dimensional.
It would be nice if there was a middleware that interface with all these different apps and devices and feeds it into "Health" app. That would be better than a stand alone app that interfaces with all the separate apps and devices, because of both Apple and MS's deep pockets to evolve and improve their own health app in the future.