>> Now I understand that Attenuation goes up when going to ADSL2+ by about 3dB is it?
On average yes... but it does depend on the router (how it records the attenuation) and how much more speed you get. The higher attenuation is because there is a wider band of available frequencies to measure the attenuation over.
If youre using the same router and its one that measures over the average tones in use rather than the whole available spectrum,
and your speed doesnt increase too much, then your change in attenuation will be small.
>> I will either get 11 or 12 meg
Theres one thing that worries me about your line Jamie and thats those gaps and dips at the higher end frequencies which are still there. Because your bit loading at that point isnt up to much, it will still be there regardless if you are on adsl1 or adsl2+ and will impact on your maximum speed.