As I said before, the Loake 1880 ~£200 vs Vass ~£300 doesn't seem like such a huge saving. If I had considered Edward Green, which are substantially more expensive than Loakes, then I would entirely agree with you and I would definitely go for Loakes for my first few pairs. It's only the somewhat unique price/quality point of Vass (possibly related to the unusual economic development path taken by Hungary? but I am no expert on that) that makes them look too good to be true. A big reason I made this thread is that when something looks too good to be true it often is - but a lot of what's been posted seems to agree with my thoughts.
You're probably right that most people in the UK (and I guess most of the world) can't tell the difference between Loakes and Vass, but still, I will be able to tell. Also I wouldn't be surprised if they noticed it on a sub-conscious level, without taking in the specifics of the shoe design and construction.
Get the Vass. It looks like you've done enough research and know what you're talking about. Check the K last, it looks quite good. You should also consider special orders as said before, they're about 600 euros which is rather attractive for MTO. I think Vass ships to Europe, but I don't know the prices.