In all, the speaker seems sturdy and should survive a short fall. A metallic grill covers the single 3-inch driver (yes, this is a mono speaker).
I wasn't particularly blown away by the sound of the Dot. It doesn't sound bad for a $50 wireless speaker, but it also doesn't sound great (I expected a little more because it's bigger than many of wireless speakers, such as the BT2500).
There's some bass and the speaker plays fairly loud, but you'll hit some distortion if you really crank it, and it just doesn't handle complicated music or tracks with lots of bass too well. For instance, when I turned up the volume on Coldplay's "A Sky Full of Stars," it did fine with the vocals (midrange) but once the heavier bass line kicked in with the chorus it sounded pretty messy. The same was true for techno and hip-hop tracks.
The moral of the story is that you just can't push this speaker too much or it'll end up with a harsh edge. That's true for a lot of these mini Bluetooth speakers, but I was hoping the Dot would exceed my expectations. As it was, I thought I might be better off with a smaller speaker like the Divoom Voombox Travel, which also retails for around $50 and is water- and shock-resistant and has Bluetooth 4.0, which makes pairing a little easier.
Battery life is rated at 8 hours, which should allow you to get through most of the day (at least the daylight hours) on a single charge. You may be able to get more battery life out of the speaker if you keep the volume at more modest levels.
Ultimately, the biggest strength and standout feature of the Philips Dot is its design. It's attractive and unique looking and has the added benefited of a weatherized finish that makes it splashproof. I didn't think its sound was great, but for its modest price it's fine for noncritical listening and will serve well as a background music speaker both indoors and outdoors.