Usually different motovlogers, people I work with, and the internet. Since they all say your main sitting position is leaning forward, and I don't have that great of a back for long periods of forward leaning.
Also haven't read it. Saw the post just before leaving to work, and currently on lunch.
Be aware that what feels comfortable in the showroom, while a bike is not moving, is COMPLETELY different from how a bike feels while riding it.
I find a cruiser position to be very hard on the lower back, once you are moving, and the wind is an invisible hand pushing you back into the seat, with the forces concentrated on your lower back (because on most cruisers the pegs are forward in varying degrees), and with highway speed winds creating enough force to become downright painful on the lower back. I also find that the cruiser position is less than optimal for precise control. This is even more critical for a new rider. There are plenty of neutral position bikes that not only offer better control, but they ARE easier on the back, on ALL rides, from short spins around the block, to day long rides.
MANY of the milder versions of sport bikes actually offer a more neutral position, and do not position a rider with much of their weight on their wrists on clip on handlebars. Researching each specific model will tell you this.
And to even consider buying a bike that you have stated you don't really care for the looks of? Big mistake, IMO. You want to be proud of your machine, and look forward to seeing it as you walk up to it before every ride.