I've used both the Anker and Jackery Bar with good results from both. The Jackery Bar offers more size options with the ability to recharge a Samsung Galaxy S5 1.5 times to more than 4 times. However, as the charge capacity goes up, so does the weight.

For day trips, I use a small Jackery Bar as 1 recharge is more than enough (my MapMyHike app draws a lot of battery). For overnight and multi-day trips, I bring a larger Jackery Bar with up to 3 recharges available...or I leave it home.

From a weight perspective, the Anker is lighter than the Jackery Bar for the same level of charge, but the difference is only a few ounces - hardly enough to scoff at unless going on a long trek and every ounce counts.

The long and short (or perhaps heavy and light) of it is that I don't think you could go wrong with either of these options...