Though Apple never mentioned the battery capacity on their website, during our review of the device we found that iPhone 8 does have 1821 mAh Li-Ion battery.
iPhone 8 does support fast charging. Apple iPhone fast charges up to 50 percent in 30 minutes when you use an Apple USB-C to Lightning cable and one of these adapters: Apple 29W, 61W, or 87W USB-C Power Adapter.
Yes, iPhone 8 is slight heavier than iPhone 7. Apple iPhone 7 is 138 Grams while iPhone 8 is 148 Grams.
Yes, iPhone 8 does have the stereo speakers.
No longer the gold standard, the iPhone 8 is still all the phone you need.