I love the convenience if carrying only one device around. Personally, I would rather carry around one smartphone with a large display and very good battery life. That works for me. However, it does not mean that there are no merits to the idea of carrying two devices – a smartphone and a tablet.
You see, if you have a very long day out – and especially if the day is hectic – a dual device strategy means that your smartphone battery will last longer, all things being equal. While you are working (or playing) on the tablet, your smartphone gets to rest from your constant typing and swiping. Because an active screen is one of the biggest consumers of battery on a smartphone, this means that your phone battery gets to last longer.
The truth is that even the phones with really good battery lives tend to get stretched and need a topping up on a very hectic day at work. And if you are away from a charging point or do not have a power bank handy, you might still end up with a dead phone. So, there it is. What is your preference: carrying only a phablet, or carrying a smartphone and tablet combo on an intense day away from a power source?