I'm not an expert but.....
This from internet research and owning a couple:
Applies to CRDI but I'm sure petrol is similar
up to 55
XE and XS models with 110 BHP fixed wastegate turbo engine and 5 speed gearbox built in Korea
XS has leather heated seats, climate control, tinted windows, cruise control, Electronic Stability Program auto lights, electric sunroof, shopping bag hooks, metal sill kick plates, tinted windows, rear load cover.
XE has less - haven't owned one so not sure.
XE and XS now 138 BHP with variable wastegate turbo and 6 speed gearbox buit in Korea
XS same as 55
57 - change year - some built in Korea and some in Slovakia - Korean ones are 'old spec' and Slovakia ones are'new' specas now 3 models instead of 2
08 - 09
Now 3 models - XE, XS and Titan all with 7 year warranty
all have same engine with VGT and 6 speed gearbox
XS loses heated seats, sunroof, shopping bag hooks, ESP, metal kick plates (plastic instead), load cover. I think Titan is the same as 'old' XS but with 17" wheels.
All models get uprated (stiffer?) suspension and bigger brake discs.
Headlights are 'darkened' (?)
Front radiator trim only has one silver 'bar'
Tinted windows are stick on tint - not tinted glass as was in Korean models
09 - 10
More revisions - headlights redesigned (indicators different)and front foglights are round instead of 'shaped'
I think back to 2 'bars' on radiator grill
Still 3 models.
Personally I think the best one to get would be an 08 - 09 Titan CRDI with 16" wheels ...... I believe some dealers would change the wheels if requested.