The major differances for a long time were just a sticky label with a different UK price and maybe ISBN (The Titan version been more expense). There was a major hoo-ha about this many many months ago but given things changed last year with Diamond taking over from Titans, you won't be getting that anymore

There has been changes sweeping across with UK stuff anyway. How long Panini will keep doing their own versions of TPBs outside of their own compilations I don't know (Wish I had all the different versions to compare myself.). Certainly with Diamond dropping the Marvel/DC UK monthlies from Panini/Titan at the beginning of this year and the recent dropping of the Panini forums, one wonders where this will lead to?