Kef R11 meta good pairing with Rotel RB-1552mk2?

Nothing wrong with that pairing.  

It will work, but you might not get everything from those speakers with that amp. The KEF’s are 4 ohm speakers and typically crave power. While the Rotel states it is 4 ohm stable, it is conspicuously missing a wattage spec for 4 ohms which tells me it will struggle with impedance dips. Ideally you want wattage to double when impedance is halved, but plenty of decent amps don’t achieve this and still sound good. Not publishing that spec is a bit of a red flag, especially when considering a speaker that is rated at 4 ohms nominal impedance. 

@zlone Yep, I noticed the 4 ohm spec was missing too.  Kinda odd.