I had a 2018 Scott Scale 910 in large that I sold last summer, I now fancy a new one.
My main concern is around geo and sizing, the Reach and Stack on the old large is 443.2mm / 617.7mm, on the new Medium the Reach and Stack are 442.8mm / 605.3mm so the reach is basically identical, stack is a spacer different. Now on the new Large he Reach and Stack are 463.3mm / 614.6mm, so identical stack to the old one but a fair chunk more reach.
What I don't want is to end up with a bike that's too long, so is reach the best figure to go off? FWIW I'm 179cm tall so smack in the middle of the size overlap!
How much dropper do you want to run, and how long are your legs?
FYI - 178cm here on a Medium current gen. Was able to finally buy one as the current version has a sensible seat tube length relative to the reach.
Last one had a 120mm drop dropper, which is more than enough for me, from what I recall I have about 250mm of post out inc. The dropper bit, leg length is around 32.5" / 825mm inside leg