I too have heard (pro bike fitter/physio who worked a lot with Spesh UK/BG/Retul) that the starting point for Specialized saddles is the centre portion flat (ignoring tail and nose). This means for some models the tail rises and nose drops (Romin, Power), some end up almost totally flat (Toupe), all depends on shape and therefore your preference is shape dictates what saddle you buy.
The Power and Power Arc are designed to be set with the rear of the saddle approximately where standard Specialized saddles would sit, with the nose 3cm back. There is a little variance here, the Toupe for example has a slightly longer tail than most and a Romin a longer nose. That might mean ‘like for like’ it needs to be a little further back or forward.
Being conscious that the pro-peleton isn’t always to be followed, but it is interesting to note, at the Vuelta a Murcia virtually all the Bora Hansgrohe bikes had ‘modern’ saddles like the Power/Arc and the majority were obviously nose down and some extremely so.
I briefly tried an Arc set visible nose down and it felt great for spirited riding on hoods and drops but terrible on tops. If you were a crit racer it might be worth some experimentation. As said above my preferred position seems to be set well back like a traditional saddle.