Definitely 2005 IMO.
The differences, whilst no doubt improvements, are so subtle that I can't see it's worth the extra unless you have to have a new car. Some bits of the interior seem to have been changed unecessarily and not really for the better.
I doubt you'd notice the extra power unless you ran them back to back.
All Zeds are fantastic cars and you won't be disappointed whichever one you choose but you may be a bit poorer.....