Same problem here.
I’m 6” and their sizing calculator recommends a Medium Spectral. Playing around with it a bit I spotted that the only body measurement that makes a difference is the inseam, mine is 86cm, push it up to 88cm and I go Large. This seems quite a basic calculation as I would expect torso or arm length to also have something to do with it.
The frame reach is also the one that concerns me: 415mm (M) and 440mm (L). Medium just seems too cramped looking at the numbers. For comparison I rode the Remedy 19.5” which feels right but has a 432 reach. I suppose this is the dilemma of buying online.
Keefmac did you throw a leg over the Spectral at the Bike Show, how did the reach feel?
I think I might be over analysing this! Does 25mm reach matter that much!? Maybe the Spectral is just a more upright riding position? Can any owners confirm?