I've owned mine for about 5 yrs and couldn't be happier. Interestingly enough, I had occasion to speak Roger Modjeski a few years ago and when I told him I owned a pair of Spendor S100's he suggested I try connecting to the 4ohm tap. I didn't and didn't think much more about it. I was reading a thread somewhere and this was brought up again, so I figured, what the hell, let's give it a shot. All I can say is , Holy Shit!! At 1st I made the switch, turned the amp on and threw on some Latin Jazz, was thoroughly unimpressed. Although the highs sounded clearer and more distinct I felt like there was a bass suck-out. Bass was more tuneful but it seemed that there was simply less of it. Cut to an hour later, I'm reading and listening and all of a sudden my head lifts out of the book, THERE'S the bass, rich, fuller, and deeper while being more melodic. Without being able to measure it feels like I gained an octave at the bottom end! All I had to do was wait for the RM9 to warm up! This sparked a late-nighter, I went to bed at 3:30 in the morning thinking about what I was going to listen to today!. Man oh man oh man, if you own a RM9 and your speakers don't present too demanding a load, you simply've GOT TO give this a shot! Woo-hoo!! Much improved sound without spending a penny! I'm kickin' myself for not listening to Roger years ago!
Bottom line on the RM9; I've never read anything but positives about this amp. Built like a tank, mechanically dependable, year in, year out, exceptional sound that can be tweaked to one's liking in any number of ways. Not to mention how pretty she looks when she's fired up, tubes front and center (I've NEVER used the tube cage!;). Tell ya this much, what I HAVE read, time and time and again, is buyer remorse after selling theirs. IF I ever decide to go with another amp, you can bet yr booty that I won't sell mine, NO WAY!!;)