I have one of these and it's a great deal. For a start the '3' network is 100% 3G coverage - i.e. they don't have a 2G licence, so you'll always get 3G. Where I live, in the North East of Scotland, their coverage is excellent, even in the rural area where my house is. The actual MiFi unit itself works very well indeed. It comes with a mains charger, but it will charge just fine from a USB port. Be careful, the connector on the MiFi looks like USB, but it isn't, but 3 supply a USB-to-MiFi cable, so there's not a problem. The display on the MiFi is great - it indicates signal strength, battery, number of WiFi connections, network name ('3') and other status information. Battery life is about 4-5 hours with no problems. The unit really is switch on and go - I simply inserted the supplied PAYG SIM and switched on and it was up and running. The supplied SIM card comes with about 100MB of free data, but you can always (even if your card runs out) surf to the 3 website, so that you can top up using your credit card. Any activity on the 3 site doesn't count towards your data usage. My only complaint is that the PAYG data is time limited to a month, use it or lose it. Having said that, it's highly recommended. The unit is really small - the pictures on the Internet make it seem bigger than it really is. It's easy to drop into your pocket. If you're going to use it with the iPad the only problem is that you can't charge the MiFi and the iPad at the same time with a single charger. i.e. if you had a regular laptop you'd be able to power the laptop with the laptop's charger and charge the MiFi from the laptop's USB port. With the iPad you can't do that, so you either need to run the MiFi on its internal batteries or take the MiFi charger with you. Not sure if you could use a USB 'splitter' to power the iPad and charge the MiFi from the iPad's USB charger. Might be worth a try.
Tim
Scotland