That Rocket RS550 MKII looks very nice, even though never heard one. However, I have noticed that they have a 6 ohm impedance vs. 8 Ohms for M60s that I have. I don't know whether your receiver can handle that. Also, considering its efficiency ( 88 dB) you would really need a powerful amp or receiver (let us say 100 wpc rms). Further, it is not possible to bi-amp or bi-wire with Rockets (only one pair of binding posts at the back). I have my M60s bi-wired.
BTW, I am very happy with my M60s in a stereo only setup.
