Re: A fully spec'd 15'' macbook pro is now £6209.
This is not a laptop. As you say, it's more of a desktop-replacement.
How much does it weigh?
Personally, I can't stand Windows 10. I'd rather pay more for something I like to use than pay less for something that I hate switching on.
I don't need any of the Windows-apps, there would be no benefit for me to switch to Windows, except saving a bit of money every couple of years.
That said, I currently don't need a laptop anyway. My hardware-requirements are very modest (satisfied with a 2012 i7 MacMini, 512 GB SSD, 16GB RAM).