I borrowed a Megaboom 4 for a long weekend and it survived a backyard barbecue, two evenings on a dock, and one accidental shove into a pool by a four-year-old who was very pleased with himself. The speaker floated. The music kept playing. The four-year-old got asked to fish it out, which he did. That is the use case the Megaboom 4 was built for, and within it the speaker is more or less unbeatable.
What UE got right is durability and form factor. The cylindrical shape with 360-degree sound is exactly correct for a speaker that gets parked in the middle of a group of people, because there's no front or back to face — wherever someone is standing, they hear roughly the same thing. The IP67 rating is real, and the speaker actually floats, which is more useful than it sounds the first time it ends up in water. Battery life is the strong point of the whole UE line, and 20-plus hours at sensible volumes is the kind of number that means you charge it on Friday and don't think about it until Sunday.
The tuning is built for the same use case. Bass is forward, mids are recessed, the overall signature is the kind of thing that sounds energetic at low quality and continues to sound energetic across a backyard. Electronic music, pop, and anything with a strong beat all land well. The speaker is loud enough to fill a deck and clear enough to carry over conversation, which is the actual test for a party speaker.
Where it falls short is anywhere you sit down to listen. The mids are thin in a way that flattens vocals — singer-songwriter tracks lose the body of the voice, acoustic guitar loses the wood of the instrument, anything that lives in the midrange comes out a little plasticky. Push the bass hard with a lot of low-frequency content and the passive radiators will start to distort audibly, which is the speaker telling you it's hit its limits.
The other honest critique is that the Megaboom 4 sounds almost exactly like the Megaboom 3 did. UE has not done much to evolve the sound signature in two generations, which means if you already own the previous Megaboom there is almost no reason to upgrade. The differences are around the edges — slightly better app, slightly different aesthetic — and the audio experience is essentially the same speaker.
There's also no USB-C audio input, no Wi-Fi, no AirPlay, no multi-room outside of UE's own ecosystem. This is a Bluetooth speaker in the most literal sense. If you want any of the smart-speaker features that other portables now include, this is not that product.
At $149 on Amazon the Megaboom 4 is the right speaker for a specific job — the loud, wet, rough-handled party speaker that doesn't need to sound subtle. The JBL Charge 6 at $199 does better mids and bass, has USB-C audio, and feels like a more modern product overall; if you're choosing between the two for general use, the Charge 6 is the smarter pick.
Verdict: Buy this if 360-degree sound and the ability to survive a pool are higher on your list than midrange detail. For music listening at home, a JBL Charge 6 is the better tool for $50 more.