Awesome product! I really liked my Grace waterproof case with speaker. I say "liked" because it was so good some low-life at the Chattahoochee River takeout noticed it and decided they needed it more than I did. I bought it last spring and used it a couple dozen times over three months while floating the Hooch in a tube and in my kayak on the lake. I'm about to order another one and thought I'd share my experience.
It really is waterproof.
Great sound for a speaker of its size.
It uses AA batteries (3)
Good battery life with my rechargeables
Cons: none really. There are a couple of things I might change, but they are personal preferences that I will note below.
The first thing I did was test it. Yeah, it sounded great, but I mean I closed it up and dunked it in the sink - without my MP3 player inside you knuckleheads. I put tissue paper inside and it came out bone dry. I noticed one of the negative reviews said theirs leaked from a corner and the manufacture rep told them to double-check that the cord does not get pinched in the corner. That happened to me a couple of times but it was really noticeable when I tried to clamp the case shut - push the cord aside and no problem. I also saw the rep says the cord has been redesigned to better plug into players/phones that are in a protective case.
It is somewhat bulky, but that is what gives it the big sound and makes it float. I actually would have liked a bit more space inside. I was using a larger-than-most MP3 player (Zune 80GB). I managed to wedge in spare batteries (I use rechargeable), ID, cash, and car key off the key ring. If the case was just little thicker I could have carried my phone too.
Regarding the spare batteries... I only carry them because I don't recharge daily. I've gone all weekend on one set without any problem. I don't doubt they get close to the manufacture's stated 30 hours.
I saw some complaints about poor sound from the speaker. I don't recall if it was in the instructions or I read it on here but if water gets onto the speaker you just have to turn it over and tap it against your palm. It handles splashes well and I've only had to do this after dunking it. If water got into your ear it wouldn't sound too good either. This speaker is the best I've heard for its size.
Another review mentioned the size of the strap used to attach a carabineer. I also would like it more if it were a smidgen larger, so I could use a larger carabineer on it. Not a big deal. I just attach my larger biner on theirs so I can clip it to my float tube handle.
And, since I know the manufacture reads the feedback, maybe make the grooves on the volume knob a bit deeper for a better grip.
That may be one of the best things about this product - the manufacture cares about the user. This case is bulletproof (no, not real bullets but it is tough). But anyone can oops now and then. In the Amazon reviews, I saw the manufacture's rep listening to the feedback and offering solutions. I sure wish other companies would learn a good lesson from these folks.
I'm looking forward to replacing my stolen speaker soon with this same one from Grace Digital. Spring is almost in the air and I gotta have my tunes... See y'all on the Hooch.
Update June 22,2012: I got my new ECO Extreme case/speaker. I switched to alkaline cells (vs. rechargables) and haven't had to change them over 8 trips down the Chattahoochee River (about 24 hours). They did make the carabineer more friendly and the audio plug also was changed for a better fit. I now use my smart phone in the case (the POS Zune player died). I've measured the inside and it looks like it will fit the larger Samsung S3 if I upgrade. Every trip someone asks where I got the great speaker/box.