I can be very wrong but in my opinion any bike you are doing long rides in regularly eventually becomes comfortable at least for me.
I am not particularly flexible but when I slammed my stem for instance it just took a few long rides and my muscles got used to it. Its also true I ride like 16 hrs/week which maybe induce fast postural adaptations for me.
I think road bikes in general have reached all very high level of quality and they are an industrially mature product. Any improvement/claim at this stage is really splitting hairs.
Take for instance the new Tarmac. Half of the aero improvements people claim comes from wheels and integrated handlebars. But then you check the Deceunik QS world tour team version and due to sponsorship they do not use the Spesh handlebar. I think improvements in bikes are now marginal and blown out of proportion by marketing.
The bottomline, we are bike nerds and like discussing about them but in my opinion bike fit, climber vs. aero bike dichotomy, etc. its all a marketing strategy lie so that they get the money out of our pockets. Maybe I am very wrong and I would accept any backslash for this comment 