Mine arrived today, on a Sunday thanks to SF-Express Shipping. Got it installed and really love how it sounds. Silky, silky smooth high end, great low mid hug. Lows sound full and natural, but with a beautiful vintage-y 1960's (or 50's) time warp to them. Don't have another M7 to compare against, but it has the characteristics I was looking for and sounds great. Now that I know, I will be buying more of these from Guosheng for sure. Wow.