I really like my Eton Soulra but it does have some less than perfect things.
I do like the sound.
It is water resistant, not 'waterproof'. Since my phone is in it I put it away during the big rapids. I did leave it out in the rain the other day when floating and it is fine. They shower test to some rating but I am not going to run it through big rapids.
It does have a solar panel to charge the battery but when you have the panel in the sun the iPhone overheats and shuts down. Small white scarf over the phone part solves that.
It does charge the ipod/iphone when it is playing music. If you leave the music player in it, it continues to charge and runs the battery down. So when I shut it down I pull the phone out. I also used some foam in the slot where the phone goes to keep it from moving around.
Also mine drains the battery in about two weeks if I don't unhook the battery under the cover. I bought two extra batteries ( $7 each) and take a small recharging unit along.
Get an extra screw for the battery cover too. If you have one of the really big phablet type phones it won't fit in. ipod touch and iphone work great. There is an auxiliary input 3.5mm plug in but it won't charge the device.
That is all I have. Less than perfect but would do again. Under a $100.
Amazon.com : Etón Soulra Solar Powered Sound System for iPod and iPhone (Black) : MP3 Players & Accessories
I like to have river tunes.