It appears that this 'max' broadband trial *isn't* based on ADSL2+ technology then according to the link that you posted, as this is mentioned on the BT website:
"While existing ADSL technology will be used to provide rate-adaptive downstream line speeds ranging from 288 Kbit/s to 8 Mbit/s, BT Wholesale is currently conducting internal technical trials using ADSL2 + technology as well as evaluating VDSL technology and aims to deliver downstream speeds of up to 24 Mbit/s +. BT Wholesale aims to announce its plans to conduct wider tests for ADSL2+ and VDSL in 2006"
I don't know whether I will be any better off with either 'max' broadband or ADSL2+ to be honest as I have NO way of knowing how long my telephone line actually is?
I have been to click here and entered both my telephone number and postcode and I now know that I am 2.86 km from the exchange but that is ONLY the straight line distance NOT the actual length of my line which could be considerably longer.
I suppose I will just have to wait and see whether I can have access to a faster broadband service when the time comes!