To tell the truth,I always preferred London as the place for a Euro Disney,but now I've come to believe that,in the long run,Paris was really the way to go.It's in the center of Europe,it's got a very convenient transportation system,all this combined with Walt's french ancestry.After all,Eisner was not a man of mistakes..
Compared to France though,UK would be better in terms of hospitality,a MUCH friendlier domestic audience (remember when the French attacked Cast Members? :shock: )AND *sigh* would alas be English speaking...
London's drawbacks,though,would be worse weather-imagine Heathrow covered in fog causing even 6-hour flight delays(personal experience)- ruining trip planning,as well as be more distant to continental Europe.
And,of course,now with the Eurozone,-almost- all other European countries would have to switch to British Pound..!
As for Spain,despite the good weather,I don't think it would fit in to the Disney spirit as well as Paris...