Any idea Neil why my attentuation is much worse than the house four doors down?
ADSL2+ is partly responsible, as it uses wider frequencies the attenuation is measured differently. Attenuation does not just depend on the length of the line, the actual condition of the line also effects it. There may be a fault on your line which is effecting its efficiency, thus increasing its attenuation.

How will that improve the speed?
As mentioned ADSL2+ uses much higher frequencies than G.DMT, this makes it more susceptible to noise on the line. Long lines, with very few exceptions, are much noisier than short ones so ADSL2+ does not perform so well. There is really little advantage in using ADSL2+ on a line which get less than 8Mbps.