SMSL amps rate at 1khz and 10% thd, assuming they rate the same way they are presented on ebay. Now I know to the folks around here, that's sacrilege and a good enough reason to never take a chance on these little amps.
However, GranteedEV and I have both had amps from this company that we purchased from ebay and they have performed admirably. As long as you go into the purchase with the right expectations, I think that you can be pretty happy with these amps. FWIW mine is rated at 65w/channel at 10% THD. So realistically, I'm probably getting around 40w/channel or so with acceptable THD. With whatever power it's supplying I've been able to drive the SVS Ultra Bookshelves (87db/2.83v/1m), Jeff Bagby Mandolins (85db/2.83v/1m), and the Phil 3's to pretty satisfying levels in medium sized rooms from about 14ft away.