Gurus... I'm have a MiFi from 3 UK. I use preloaded SIMs, that come with a 3 month/3GB allowance. As 3 now have their "Feel at Home" service (free roaming in various countries for voice, texts & data), I want to use it in the USA on a future trip, but I gather that this particular MiFi might not be compatible with the USA networks (Huawei E586). So, if that's the case and the MiFi is a no go, I was wondering if I could simply put the SIMs in either my 5S (or my Wife's 4S) and just set it up as a Personal Hotspot for tethering? Cheers.