I've had the SM6.1's since 2001. I think they're very good indeed for all types of music from chamber and jazz to orchestral and rock. I hear detail, more than adequate mid-band and bass, no screeching highs, and an always convincing overall presentation of the music. Living in a London flat, and accommodating the speakers in a spare bedroom, though, I very rarely turn the volume up to the 'realistic' levels audiophiles often speak of.
I've got no time or taste for comparative listening, so can't say anything useful about how they stack up against other speakers. They've worked well successively with a Pioneer A400, nOrh SE9 and SI T-Amp, the latter combined with a Xindak valve pre-amp. In the coming years, I'm more likely to upgrade my turntable or pre-amp (to get a tape monitor circuit and more inputs) than the speakers, though I have toyed with trying biamping with another T-amp (mainly out of curiosity and because T-amps are so cheap).
I consistently come away from hifi shows wondering what all the fuss is about but that's probably as much to do with the choice of music and the hotel rooms as the equipment!
Bottom line is that the SM6.1's have been a great-value fit-and-forget purchase for me for the last seven years.
