I reply to all who ask me in private a number of personal considerations on bikes that I personally ride, unfortunately you are in many (thanks!) and I can not answer at all. Fortunately, you do all the same questions .... To which I gladly reply:
I would buy this bike and why?
No, because I do not consider convenient brakes integrated into the frame
Defects? The rear brake requires a certain habit to be used
What would you change? Nothing
What upgrades would you do? Put a SRAM Red groupset
Is it a bike suits for Granfondo? Certainly
Is it a bike suitable for uphill? Yes.
Its performance is competitive? Yes.
What alternatives are there to this model?
Alternatives are always endless list, here some that are direct competitors:
Bianchi Oltre XR 2.0
What is the main advantage of De Rosa compared to direct competitors?
The build quality and versatility of use
I want the bike with the best price performance/ratio, De Rosa is okay?
Contrary to what you think, the Frame Kit King XS has a cost of about 3000Euro, is not much, although there are cheaper products.