There were also a few "oops'" where some of the Euro only pieces made it in to a US pack. I remember a player pulling a Stix in a sealed event (fresh case just cracked open for the event). I had also seen similar mentions on the forums at the time.

At our events we saw several UK Indy stickers inside the dials of US figures.

The boosters were also slightly different. The american version was red in the lower 1/2 of the background, the Euro version was gray.

I just finished my Indy Uk set last month with the last 4 that I needed. WOOHOO!!

I loved playing the Euro Clix back when they came out, selection was still low at that time and they were a refreshing change.
I still love the Brit City Judges generics, still very good for the points.
I broke out Nemesis for DHC last year and was asked if he was from Mage Knight by another player.
There was a bit cool factor having him on the table during the Indy round.

Too True. I love the Brit Indies. Having always been a 2000ad fan, my son surprised me with a case of British Indy boosters for my birthday 3 years ago. At the time, I already had a few, and between the case and a couple of gifts from friends, I ended up with the complete set plus the promo pieces.
The Nemesis remark made me chuckle because I heard the same thing when I played him.
The cool factor is often combined with the surprise factor when you play these figures. I beat a metal men team (including alloy) with a 2000ad team featuring british Indys + Judges Anderson& Hershey. My opponent never saw them before and was a little tentative.(thankfully!)
I also fielded a team at clix for the cure with a couple of other players and their teams vs a Judge playing the sinestro corps & sc anti-monitor. I was totally outclassed (anti-monitors av was higher than Wulf's dv!) but we all had fun. I still break these figs out on a regular basis. I find them fun to play and awesome to look at.