We just picked up a Goal Zero Guide 10 Plus, after using a friend's on a sheep hunt last month. The bonus to getting the "plus" model is that it comes with a battery pack that can be recharged off the solar panel and then used as a stand alone. The solar panel itself will charge devices, but if the sun goes under a cloud it will stop charging. The battery pack charges off the panel, and then can be used to charge anything you need to whenever you want as the charge is already stored. Bonus is that it operates on rechargeable AA or AAA batteries, so in a pinch you can even pull the batteries for devices like headlamps or gps. Looking forward to playing around with it more on our trip to Kodiak next week, and will give a full review once I have put it through the paces
I have been disappointed with the mophie reserve pack I picked up (albeit on clearance), as it seems to not work as well as it used to. Particularly in cold weather, I can only get about 30% charge now, when I used to get at least one full charge out of it...
Some of their other products and packs come highly recommended, so maybe it's just the model I have.
We never have reception! But audiobooks on the iPhone in airplane mode have saved the day on a couple of recent trips. Picture me, Luke and two other guys crammed into the SL5 for most of the day waiting out a wind and rainstorm...we drank coffee and listened to a story about a ship frozen into the ice during an expedition to the north pole and suddenly our weather and situation seemed a little nicer!
I used the Goal Zero Guide 10 plus on the mule deer project hunt. I echo what Becca has to say about it. It definitely needs good sunlight to charge well. I love the versatility of the power pack. I have 8 AA batteries and 4 AAA batteries so I can keep rotating the batteries as needed either in the power pack or in my electronic devices.