Just switched my wifes iPhone 4 from O2 to Virgin Sim Only when her contract ended.
It’s been fine.
I’ve cut down SIMS before and it’s fine to do that if you use a fresh blade in a Stanley knife.
[sales mode]
I have a black 16gb iPhone 4 I’m waiting for Orange to unlock and I will then sell it. Comes with a LifeProof case and is in A1 condition.
email in profile if you’r einterested.
[/sales mode]
[edit] having said all that I’d phone Virgin and get them to confirm that the SIM/phone/them are all compatable before spending any money…
[edit 2] It’s got 16Gb of memory, not 8.