Clive Mott is a highly respected Motorhome journalist and has made many good contributions down through the years.
You should also investigate this site.
http://www.aandncaravanservices.co.uk/ Read their take on lithium and also the article on campaign for battery change.
Alan, who passed away a few weeks ago, was probably the most knowledgable contributor to many forums on all things electric. The thing that stood him apart from others was that his firm does not sell batteries and hence are as impartial as you can get on best value batteries.
The article on lithium is well worth the read, and as for the NCC battery scheme, well it is now under investigation by trading standards due to the fact that it does not appear to stand over the claims it makes for the batteries.
AandNcaravans are essentially a repair outfit for anything electrical (particularly control systems) and have years of experience in battery quality, suitability and lifespan. Items that appear in magazines such as MMM (out and about live) are always subject, in my mind, to editorial pressures. How often have you read an article on a Motorhome that is critical of design or build quality. Having said that, out and about live Motorhome forum contains many good discussions (including some hot and heavy) on lithium and the NCC scheme.
Davy