Since my Fitbit Charge 2 died in less than 3 years, I needed to replace it, but I didn't want to pay the price for another Fitbit when my last one didn't last long. I've used a Mi Band in the past (the 1S version) and I was pretty pleased with the amount of features for the price (especially the looooong battery life), so the Mi Band 4 with it's new full color screen was an easy choice at under 40 dollars.
I found an ebay seller who had Mi Bands and I snagged one for $35 and free shipping. Rather than purchase from Aliexpress, Banggood, Joybuy, or any of the other popular well known Chinese retailers, I just picked it up from a US seller on eBay who has them in stock (from Illinois) and I'll have my Mi Band 4 probably next week.
Really looking forward to getting my Mi Band. I'll hook it up to Google Fit and then use Google Fit to send my Mi Band step data into MyFitnessPal, which is one of the best weight loss and calorie tracking apps for Android.
Oh, and I forgot to mention that I ordered the Chinese version of the Mi Band 4 instead of the Global version. Why? Because the Chinese version supports English (the only language I'll use) and it costs about $10 less than the Global version.