I just measured mine and Amazon’s dimensions are correct.
I paid ~$120 for a new one through the mothership a while back and have been mostly happy with it. The build quality is great and it’s very hefty. It’ll put out quite a bit of sound for the form factor and can handle a decent amount of bass if the volume isn’t too high. At lower volumes, it’s shocking how fat and robust the low end is for such a small speaker. Even though the bottom has rubberized feet and a nice little miniature kickstand to help sound project up a bit, it’ll still move around if it’s placed on a slick surface.
I had mine perched on a ledge that was just wide enough for the speaker. When a particularly bass-heavy song came on, it vibrated off the ledge and fell two feet onto a radio on another level and completely shattered the radio’s plastic display. The TDK itself was completely undamaged.
I’ve got mine paired to a phone and a tablet and it has no issues connecting to either device. I use an app called Music Volume EQ to tweak the sound for a little less bass and a little more treble and the speaker handles it just fine.
The biggest down side so far is the short battery life. I get ~3 hours of play time with Bluetooth or using the Aux In. Charging seems to take forever, at least 5-7 hours, maybe more. The full size USB slot on the side is for charging a device, but with such short battery life I’ve never even tried to use it. The charger for the speaker is a barrel connector type so if you lose the charger you may have to go to Radio Shack or online to find a replacement.
Now that I’ve had mine for about a year and a half, sometimes it goes into a “safe mode” if the music is too loud, wherein it drops the volume and the low battery indicator starts to flash. Turing the volume up just makes it panic again. The solution is to power off and then turn the physical ON/OFF switch to OFF for a few seconds. It’s not a huge deal if I’m handy but I often use it in the bathroom while I shower and I don’t want to get out just to reset it. I’m hoping this is a glitch and not a sign the battery is starting to die already.
It’s not meant to be replaced, but apparently it can be done with the right tools.
Last but not least, it can answer calls and act as a speakerphone. I’ve used it twice and the caller’s voice was clear and easy to understand but they found my voice slightly muffled. Probably OK in a pinch but better just to be used as a music speaker.