I was about to agree with the complaint until I read the ASA conclusion. Do consumers care how their internet services are delivered? I'd agree that they don't, that the speed they're going to be able to receive is what they'd make a decision by. However, the speed alone gives a 'rose tinted' view of the service they'll then receive as the number of people sharing that service along with a whole lot more factors will effect what they are able to actually get.
What would be good is a break down of the package they purchase, if it's full or part copper/fibre, the contention, traffic shaping, drop off at peak hours etc would all help to make a decision. You could have full fibre with crap throughput for example.