I’ve been put off by privacy concerns, a feeling of “I don’t really need this” and wondering whether or not they are actually effective.
I’d be interested to hear peoples experiences with them and whether they have had a positive effect in their own right.
Combined with calorie tracking I've found it's helped with weight loss as I can measure my calories burnt versus consumed more accurately. Before this I had a habit of starting dieting and working out more which lead to me drastically undereating and feeling awful after a week, then I'd default back to my older patterns. Now I am achieving more sustainable weight loss.
My watch has a GPS also for tracking runs or cycling which I've found really useful also, it's much more reliable than a phone.