I haven't compared the 218 vs the 818, but I have had the chance to put it up against the MS200 and MS600 using Speakerlink - feeding both into a G65 and straight into a pair of 5200SE. In both these scenarios i personally believe the 218 is the best option even when not using MQA. It makes the others feel a bit "rough 'round the edges". I wouldn't say the difference is night and day, but its there.

Cinema: G65, UHD722, 210, DSP520.2, DSP320.2, DSW.2