I've used these home and abroad for ages now in my iPad and
mifi unit and they're absolutely brilliant. That's a really good price for the 24GB sim
One tiny word of caution about using it overseas... in Europe last year I discovered that 3 have a monthly fair usage cap on roaming data. I'd bought a 24GB sim but wasn't allowed to use it all in one month without incurring extra charges, so now I make sure I've always got two sims to switch around. I don't know if they still have this policy though - could be old news now.