Difference between the UK and US edition of Robin Hobb's books ?

[Dan Gerous]

Hi everyone ! I'm French and I would like to purchase everything Robin Hobb wrote about the Realm of the Elderlings, but Amazon gives me the choice between the American and the British edition (both by HarperCollins). Is there any difference in the text or is it the cover that changes ?
I went to WHSmith yesterday to ask if they knew anything about that but nobody could tell me. I plan on hitting Shakespeare & Co (great english litterature bookstore near Notre Dame, definitely take the time to go there if you are in Paris) after work, but if any of you could tell me it would be nice.
Thanks,

BigBadBox

 

[sparkchaser]

Extraneous "u"s for one. And the substitution of s with z.

 

[Sneezy]

So proper English then.

 

[sparkchaser]

So proper English then.

Hush, dwarf.