O2 may not offer the best value for money for iPad tariffs but offer features which are worth a look for your iPad. O2 have a number of plans to choose from which will cater for the iPad usage you may require.
With O2 you can obtain a free SIM card with the option to top up when you desire. O2 also have plans which a prebundled to get you using your iPad without delay.
As with most O2 plans you get the option to choose from either 12 months deals or 30 day recurring plans which you can cancel easily.
O2 iPad plans are also easy to manage and you can do this directly from your iPad. If you should have any issues, O2 have UK based customer service representatives which are able to help you with any queries. Additionally all plans come with O2 wifi hotspots available for free from public hotspots, this is free of charge and the download does not count towards your allocated data included in the tariff.