I own the ridiculously small Bose Soundlink Mini, which I sometimes use when I give English language lessons. Its deep bass is miraculous.
Yesterday I connected it to my Yamaha MoXF and tried if it is completely useless for home use amplification: it is NOT.
As you see in the video, it is barely bigger than the MoXF display and you can use it for piano amplification for yourself, I didn't hear any distortion. Incredible speaker. The piece I played is "A foggy day".
http://youtu.be/8B46tubuAMM