Question on Little Dot amp

I'm looking into buying a Little Dot MK II or III amp/preamp as I've heard good things about them. Before I buy it I was hoping someone could tell me how it sounds as a preamp. I would use it mostly in my stereo but some for headphones. I've heard mostly how great they sound as a headphone amp so if you've used it as a preamp let me know what you thought of it.