I buy sound equipment primarily based off sound quality. I've had a SoundFreaq Sound Platform 2 (with battery option, subsequently discontinued) for several years and have been searching for another BT speaker that would rival that unit in both loudness and sound quality while providing a little more portability. I tried all the units off the shelves at the box stores including other JBL's, Bose, UE/Logitech, Beats, Sony, and they all were disappointing in comparison...until now. The JBL Xtreme finally delivers something comparable, if not better, than the SoundFreaq in both volume and sound quality, in a form factor that at least makes an attempt at portability (unlike the SoundFreaq). In A/B testing the unit against the UE Megaboom, SoundFreaq SP, a Sony XB40, and a JBL Pulse 2 (oldest of the bunch), the XTreme and SP were in a league of their own. The highs on the XTreme are tuned to provide a very crisp, "open" sound (but not harsh) while simultaneously maintaining the strongest bass output of the group (not unexpected since the XTreme is also the largest unit). Both the XTreme and SP provide ample volume (noticeably more than the others), strong bass (for their size) and very good, open sound quality across a range of music, with the several year old SP surprisingly holding it's own against JBL's latest and greatest XTreme. In terms of portability, the XTreme is designed for it, whereas the SP is designed to sit on a desk, therefore the XTreme is a clear winner in overall functionality.
That said, the XTreme has what I consider a design flaw around the charging ports, which are hidden behind a zipper...yes that's right, you have to "unzip" the unit to access the ports, and the pouch is a rather tight fit requiring a two handed operation to hold the pouch open while trying to connect your charging cord. And, that charging cord is not USB, it charges off A/C, meaning you need an outlet.
My Ranking (based on sound only):
1 (tie). XTreme
1 (tie). Sound Platform 2
3. UE Megaboom
4. Sony XB40
5. JBL Pulse 2 (note this is a class down in terms of year/models)
Fix the (inevitably will break down the road) zipper thing and provide a USB charging option and the XTreme would be a 5 star unit based on the loudness, quality of sound, and portable/water resistant nature of the design. At $299, the price is a little steep for what you get (these are still smallish, battery powered BT speakers after all), however, on sale ($200 range), this little unit packs a punch and is a great bang for the buck compared to the competition.