Their coverage of it in other areas of the magazine, particularly Informed Sources, has been much more disappointing. I just don't expect any different from the feature articles because I don't think that's what they're there for.
Roger Ford appears from his writing in that column to be in favour of it (in summary he can afford to pay more/mostly travels on business, doesn't require flexibility, and prefers the lower loadings it causes - that is, the outcome, which is of fewer passengers each paying more resulting in revenue neutrality, is to his personal preference). As Informed Sources is written by him, this is not surprising.
This is probably also what LNER is seeing in their surveys. Those who use Advances booked well in advance will prefer it because they aren't having to squash past standees to get to the loo/argue about reserved seats and aren't themselves seeing big fare increases, for instance. I've not read the surveys, but I suspect they're strongly weighted towards this sort of aspect of it.
If there's indeed proposed to be a similar trial on a shorter route on TransPennine Express, which seems to be rumoured upthread, I can see things being quite different. People generally value flexibility a lot more on shorter journeys. London to Edinburgh is one where almost nobody will randomly decide to travel on the day. Having said that, lots of people do use Northern Advances, which are different from LNER's in that they're still offered at very attractive prices right up to 15 minutes before departure in basically unlimited numbers.
One thing I'm disappointed not to see in the magazines is how even within the constraints of it it could be made less unpleasant - e.g. how about no change fee and refundability on the 70 minute tickets? How about getting rid of break of journey restrictions on Advances, which only really serve to annoy people by being told they can't pass through gatelines to pick up a sandwich between trains and don't serve any real purpose, because most people don't have time to go around working out which longer journeys will be cheaper than the shorter one they want to make and any site that offered this would fail accreditation anyway?