US and UK editions

[dzny72]

I know this may have been covered before, and I apologize in advance if 
so.  Just HOW different are the US and UK editions of the series?  Is 
it like reading a completely different book, although I would already 
know the plot/outcome of the story?  Or is it more of replacing "UK 
terms" with something those of us in the US would understand?  Is it 
worth the effort for me here in the US to find the UK copies and read 
those as well?  Any & all opinions please. . . Thanks!!

Zaxmom (aka dzny72)