Chatime has the best bubbles in downtown. Tea is consisent too, still a bit weak for me, but I still come here often.
This location can be quite busy, but not as insane as the Dundas location. Seating is less cramped here as well.
How fast you'll get your drink depends largely on two factors:
1) The staff who is serving you. Some days, they are very efficient. Some other days, they are less professional, just chatting with each other and taking their sweet time making your drink.
2) If a pick-up order from a delivery company comes in