The old building was very interesting - a beton brut L-shape spanning the basin and running along it; wasn't aware it was Seifert. Making Paddington 'West End' is perhaps no greater a marketing achievement than Holborn being 'Midtown'.
As for "Marks & Spencer announced it was moving its headquarters there", it wasn't much of a move they were about a quarter mile east in Baker Street. FYI their branch in Chapel Street nearby has acted as their experimental site for 50 years.
How extraordinary. Interesting that permission was granted even though it is all surfaces. It works; whether it's *right*, well...
"Hoskins proposed using previously inaccessible areas, easing the visitor flow throughout and maximising levels of natural light"
Except, it seems, on that new black stair - not at all a DDA risk.
Great pic of the then Angel Centre when brand new... AHMM's work there was exemplary. Perhaps - re Industry Pro's comment - there should be an assumption that all involved in what we might call 'assumed retention' (or at least that phase) do indeed do their due diligence and hoover up everything available, from the planning file to the contemporary write ups, as they would not hesitate to do for e.g. a heritage/restoration property?
I'm not sure why the cost of the house is felt to be factor. Good architecture isn't dependant on budget, so whilst many if not most potential clients won't of course have bottomless pockets, the fact that some will shouldn't be implied to be a barrier of any sort.