Re: great?
I think if its labelled "pastiche" then I suppose not, but I don't agree with your premise. I think the building refers to earlier classic styles but isn't overwrought or random in doing so.
By your logic any building incorporating a doric, ionic, corinthium column post-Greece is not great. But we've had that discussion before.
On the other hand, I would support your argument if the label "great" only applies to thoroughly original works. And there might be a case in that.
What I meant is that 1 St Thomas is a much better looking building than 99% of what I see going up around me, most of which is kind of similar. In a sense its historicism looks original and refreshing by comparison. In fact the setbacks are pretty dramatic.