The bubble tea is very good and they have a large assortment of hot tea as well. The health drinks are also quite good and differentiate it from other bubble tea spots.
I am not a huge fan of Chinese food, so I can't comment on the food except for the fried rice which is tasty but they have recently shrunk the portion size dramatically! When we complained nothing was done and here we come to the downfall of most bubble tea places -- service.
I've never really seen great service at a bubble tea place and Go For Tea is no exception. The waitstaff is basically competent but somewhat grim and harried. If all goes well it doesn't matter, but watch out if you have a question or problem: you won't get far with the waiters or even the manager. They're not rude exactly; they're just indifferent.
Oh, and the desserts (with the exception of the toast) are miniscule and not worth it at all. Better to have your tea and then cross the street to Demetres.
In short: go for the tea, nevermind the food.