My mate has a twin Varex setup installed on his VE SS. You can see the photo of it in the gallery of the Pipewerx website (the first photo). He used the oval style with dual tips. I didn't measure it when I looked at it but up close, it looks no larger than dual 3 inch tips. In person, it doesn't seem overly massive, and I kind of wish that I got that for my Aurion. Fitting it may have been an issue though.
The one I would have like to get for my Aurion is the single tip version, and the XForce website states that it comes in 4 or 4.5 inch tips. The 4 inch tips shouldn't look too overboard I reckon. The ones on my Aurion are 3.5 inch, and I don't think 4 would be too far. But yeah, I'm not a fan of the canon mufflers. Just looks too ricey IMO. I'm questioning whether the oval barrel Varex would fit though since the stock Aurion muffler exits offset from the centre.
Edit: For reference, this is what 3.5 inch tips would look like on the Aurion (well the Sportivo anyways; but the cutout is the same size). So 4 inch shouldn't be too much larger.
Edit 2: Forgot the debadged photo; LOL.