TL, DR: No doubt the best money you will spend. Impossible to not love the speaker unless you get a lemon.
I have tried the UE Megaboom, UE Boom, UE roll, Jbl Charge 2+, the Beats Pill, Bose Soundlink. All of the other bluetooth options I had available to me I didn't bother testing them out because the ones listed above were supposedly the next best speakers in their class. So while researching I found out that the JBL xtreme was sure to not disappoint and it will be the best 300 you will spend on a speaker.
So I decided to give the speaker a chance and make sure I keep my receipt in my wallet because I thought for sure I'm taking this back.
I am glad that this speaker probed me wrong. The bass sounds completely balanced and hits like a mini subwoofer. Not tinny or overly punchy as pill, but just right. The highs are extremely clear and even at full volume I didn't hear any distortion whatsoever. I use my Samsung Galaxy S6 and my Itouch 5 when using this speaker and most of the songs I'm playing are from YouTube, which sometimes isn't the best quality and Pandora. To never here distortion is perfect.
The cons of the speaker which may bother some but not me is that when playing songs off of your ipod, the speaker sometimes skips the first second or half a second of the beginning of the song. Other reviewers said something about DSP, but I don't really know how that works so I won't speak on it. The other issue is the when playing the speaker in its normal position, it sounds as if the places the tweeters near the bottom of the speaker making it fire towards whatever the speaker is sitting on (desk, mantle, table etc). Again, this doesn't bother me neither because if you tilt the speaker back you will hear the fullness of what this speaker offers.
As most may know, I currently work as a courier in a very loud diesel truck and I needed something that was going to offer durability if it drops, semi waterproof for rainy days or accidents, and definitely long battery life. I'm only work about 6+ hours a day and I played the speaker at about 75% and I only one light from the battery went off. Even with all the rap, house, trap, and jazz bass going on, this speaker lasted. I've only had for a week so I can't speak on the long term, but I will say I have gladly thrown my receipt away because this speaker will be with me for a very very long time.
If you read all the way down to this point then you for sure are just like me when it comes to audio and I thank you for reading my review. If you still are on the fence check out the youtube reviews on this. I usually check Jims room or clavinetjunkie for sound tests.