I've had one for about a year now. It's an insanely versatile amp. I use mine for rock and hard rock (as opposed to total shred-metal) and it has absolutely no problem achieving those voicings. The cleans are awesome and since I have quite a few pedals on my board that include many overdrives (Keeley modded TS9DX Flexi 4x2, Timmy v4, OCD v4...as well as a Analogman Sunface)...I can also use those on the clean channels in addition to channels 3 and 4...it can dial up a huge number of tones.
My revolving door of amp purchases have all but ceased after finding the RK. And like a poster above mentioned...channel 3 is sublime! My previous (Mesa) amps have been an Express 5:50 2x12 and a Dual Caliber 30. I happen to think after the RK is no longer produced, it will be a truly coveted amp. One of the greats.
Also worth mentioning....this amp really can get some great tones, even at lower volumes too, so your neighbors will appreciate it as well!