You mean for use in a car? Off the bat I'd say it's a bad idea. Ergonomically the volume control isn't as easy to reach, and sometimes you can't wait until a full stop to have to turn it down. Also, even with that form factor, that's likely to obscure your vision in some way. Even reaching for the phone to control the playback will take your eyes off the road, which is also why car audio receivers with digital inputs from iPods, iOS, Androids, etc serve as the host device and turn the other device into basically just a storage device, extracting the audio and putting the display where you can see it in the corner of your eye and within easy reach on the dashboard. Also because of the form factor it likely has far from a full range response and lack low end performance, which is made worse by a car's noise floor. And for $60 you can get the Clarion digital receiver I linked
If you're not using it in a car though I'd recommend the Bose Soundlink. It's a little expensive but it's the one I've listened to and like it - bass is boosted to sound like larger speakers, but when we play bass-heavy tracks, it doesn't get overdone (I think it might have some tech that detects at what point the drivers will distort, and reduces the bass boost accordingly). However, do check comparison reviews for that vs the UE and Creative BT speakers, considering how much cheaper those are.