Hi bb1510. Thank you for the question.
To clarify, are you asking about the differences between the glazing system used between Tower A(Hornby and Drake) vs Tower B (Burrard and Drake)?
Tower A is a combination of three types of glazing system:
From Level ~1-6 is a Structural Silicone Glazed (SSG) Curtain wall system supplied and installed by Alpro Aluminum Products. L1-6 is a combination of commericial, office, and amenity space.
From Level ~L7-L52 is a a combination of thermally enhance window wall and SSG curtain wall strip. If you look at the north side of the building, there is a continuous strip of unbroken window system. These are supplied by Starline Windows Ltd. L7-52 are residential units
From L52-55 are a new type of window system which is called a Hybrid system which are thermally enhanced curtain/window wall system. These are also supplied by Starline Windows. These floors are penthouse floors.
Tower B on the other hand are full custom curtain wall system supplied and installed by Inland Glass and Aluminum with structural steel supports provided by PMC builders.
It is quite difficult to discuss the "performance" difference of each windows as these are specific to the use and the specification of the windows which is more of a question of design. What I can say, however, is that the purpose of the window, aside from the typical water penetration, air leakage, and vapour diffusion envelope requirements, is mostly for aesthetics.
In addition, both buildings are GOLD LEED certified but only Tower A is targeting interior lighting and daylight maximization points. I guess that one big difference from the two towers.
I apologize if I seem rambling on the response, as it is quite challenging to answer the question. Its a very interesting question, however, and something that I would for sure bring up to the architect and envelope designer (when I get the chance!)
