Apple Watch Series 3 vs 4

Apple Watch Series 3 (GPS + Cellular) 42mm 不鏽鋼錶殼配鋼織手環 $3488
Apple Watch Series 4 (GPS + Cellular) 44mm 鋁金屬錶殼配運動手環 $4099
其實兩部來講,一般操作會唔會有明顯上既速度分別?
因為我玩過朋友既2代,真係feel到操作有少少慢
不鏽鋼同鋁金屬除左側邊條邊仲有冇其他其他有分別?

如果隻watch只係用數據,唔連iPhone實際用到幾多個鐘?
其實我一直都有個問題想問,iPhone長期開藍芽會唔會好食電
心電圖香港係唔係都係開唔到,硬件存在不過軟件限制左唔比開?