Reason I changed is that my mifi holds it's charge for up to 3 hours which is no good if I'm out.... Apparently 3 are now offering micro sims so will contact them shortly...
Thats useful to know as I was considering using a MiFi + WiFi iPad but only three hours is not so good.
Yes, I was reading it in an article.... not on 3's new website though....but happy to cut my SIM down to size....