I understand what you're saying chaps, and trust me, I'd much rather be getting on with it and enjoying riding a new bike.
The trouble is guys, there's no bloody stock, anywhere of anything I shortlist, in the size I want.
Therefore sitting on or trying a bike (historically and understandably, a vitial part of the decision making process) is virtually impossible, that's why I'm dithering, cus it's all 'on paper' rather than based on trying or even just seeing various bikes in the metal.
I can only get so far in deciding to spend over £1,000+ without actually seeing what I may be buying.
I wouldn't buy a £50 pair of shoes without trying them on, let alone a £1,000 bike.
I think my hesitancy is not unreasonable given the current circumstances.
I never tried either of my bikes (Giant TCX1 & Trek Domane ALR5 Disc) and they both fit great.
I just used the website measurements and shop staff advice and all was fine.
At the end of the day if the fit is pretty much ok then fine tuning can be accomplished with a different length stem and/or some fine tuning of the fore/aft position of the saddle and/or straight vs layback seatpost.
I may be insensitive but I have ridden friends bikes of a similar size to mine from different manufacturers and they have all 'felt' the same. Fatter tyres (ie more than 23-28mm) are about the only thing that I can detect making a difference to ride quality.
Whyte are a well known brand in cyclist's circles and make great bikes - most non-cyclists will not have heard of Giant, Trek, Specialised etc. Who really gives a fig about friends etc never having heard of a particular bike brand?
Carbon bits make not a jot of difference to the performance of the average cyclist imo.
Get a bike with hydro discs - miles better than rim brakes despite what those wedded to the past say. They work in all weathers and are easy to maintain (ie they need very little tlc).
Ditto thru-axles - wheels go back into the right position every time when you put them back on after taking them off. No idea what the two bikes that you mention use.
That's my thoughts and not everyone will agree but hey-ho.