I had the cf and friends had the slx. In my view almost no weight difference and to make the cf similarly aero add tririg brakes and an integrated bta drink system.

FYI the adjustability of the cf front end and the brakes is simpler for idiots like me, note u can get a lower stem riser and lower bento if u want to drop the basebar and not just the pads but u need to ask for everything when u buy the bike not after. The tiny in frame storage on the slx maybe useful but I think so so. If u want a different bento could maybe get the tohan. The general fit is slightly longer lower on the six but depends on size; width of Basebar from memory c.f. 42cm slx 40cm and six is slightly more slick with rubber handles etc but again nothing so major.

Personally I recommend buy the most basic cf and change out everything to tririg type parts.

Note the mechanical gear shift canyon eats up bottom brackets for some idiotic reason the cable holder fails and u end up cutting the bottom bracket with the gear or brake cable - the paint work on some canyons isn't so great either. The cranks provided are quite long. But other than this it's a great bike. Can't go wrong.