Mr Raptor, you say its the same rate for the first few months. BUT think on.....
On the current unlimited package, your 10 squid goes to Energis and in return you can route your long distance phone calls over Energis and get the first £10 free. So, if you are careful about which network you use to make calls, you can easily get the £10 back. Their e/mail does not mention that there will be any rebate on the new £9.99 / £12.99 rates!!