Guy, welcome. You'll certainly be able to enjoy good music on your new setup, regardless of whether it's on SACD or not. SACD doesn't have any special magic that doesn't depend on the quality of the entire recording process that's taken place.

I've been enjoying classical music on my M22s for over seven years now and continue to be delighted.

The only possible point is that a more powerful sub than the 175 might be useful for some music with extreme low frequency content(e.g., pipe organ), but for most uses in a bedroom size location it'll be fine.

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Enjoy the music, not the equipment.