As some others have alluded to, I think a major decision point is how one views and focuses the subject. EFV or OVF. Reid Reviews is frequently critical of EVFs for inability to display the full range of tones in a scene making it hard to assess. While I think the SL is overall rather similar to a dSLR, there is still that same difference with the viewfinder.
I often use a Pentax K1, probably about the same size as the SL, and also the even larger Leica S2, with a history of favoring the Pentax 67, so the size/weight isn't really an issue for me, but it sure can be for others.
So the SL has many SLR advantages, while IMO suffers even with its top-quality EFV. Still, I like my Leica Q, so there y'are! 😉