I have the two (SRS-Btv5 and SRS-X1) The SRS-X1 had a quality better of sound and better duration of the battery.

I spent a long time travelling for work in 2014, sometimes spending 3 weeks out of four in hotel rooms far from home. This seemingly small speaker can produce a surprisingly rich sound and make your hotel room that little bit more personalised. Pairing up to a phone or laptop with a playlist can make evenings just that bit more tolerable without resorting to (or as well as) raiding the minibar out of boredom. I also prefer to sleep with a white noise sleep therapy track playing. This unit performed the task with no problem. With it's built in microphone, it's a great speaker phone that you can even use when video calling from a laptop. In some cases people commented that the audio coming through from microphone was tinny and hollow, but that feedback was not consistant. Other's said it sounded fine.

This is one of the best Sony product i bought. I started using it today only but i am loving this product. It works perfect with my Xperia Z, as all know Z's Speaker is very poor, so i bout this just for giving it a try * works pefect with NFC, easy to pair/unpair just a touch does everything for you. Combining with "Smart Connect" just awesome... touch and shuffle your playlist * Nice design * Good Sound quality for the money you are paying Only function i am missing in this is it should have a button or option to shuffle my music. so that i can skip tracks if i want.