Originally Posted by
sky9
You are all identifying the issues that I thought would be a problem. I have noticed one card that is free on inbound calls in some countries and reasonable for outbound calls.
I did wonder someone had found a magic sim card that covered all the bases as I clearly can't buy 4 cards. It might be that I will have to bite the bullet and keep O2

It's not 'clearly' to me - why can't you buy 1 card per country? Roaming (and specifically DATA roaming) charges are a nightmare.