The advantages of the solar (and hand crank) devices is that you could use them in the field indefinately, recharging your phone multiple times, without ever needing to plug into into a line or other power source. On the downside, they tend to be bulkier and heavier.

The morphie will allow you to recharge your phone one or perhaps a couple of times, but then you need to plug in the morphie itself somewhere to recharge it. On the other hand, the morphies appear to be very compact and relatively light weight.

For my needs, the morphies look like the better deal. I can see carrying it when traveling. If I run down my phone listening to music on a long flight I can still recharge it to use when I get off the plane, without having to hunt down a place to plug in. And when out in the boonies (but still within cell range), it gives me at least one recharge of my phone. All this for very little weight/bulk.

If I were planning to be out in the woods (but still within cell range) for an extended period, then the solar devices would probably be the better choice.