Well, on a relative architectural scale of things, if I had to choose among 45 Charles, Scientology and this, this one would get the short straw--it really is more on the tepid spec-dreary hackwork end of the 60s (late 50s?) Modern ledger. Sort of like, the Bloor Street Neighbourhood to 45 Charles' Casa I.
Thus if this demolition disproportionately "registers", it's because the existing building's so freaking huge and solid, it's hard to miss (which might, in its turn, fuel the embodied-energy "anti-demolition" as opposed to the "pro-heritage" argument).
Oh, the waffle-pattern concrete ceilings remind me of the exposed version thereof at the (late great) Parkin Aeroquay at Pearson.