tl;dr the food was OK but the service was slow and unfriendly
Atmosphere: Bangkok Garden is decorated quite nicely in the interior (once you walk past the bar as you walk in) with dark woods, low lighting and Thai flare. If I had to describe it in one phrase I might say, "1990s Thai temple" - the dark wood, gold buddha and sparse lighting remind me of some of the Thai temples I have visited.
Staff and Service: the front staff, who I assume included the manager, were incredibly friendly; unfortunately, the rear staff (including our server) was quite a different story. It took ca. 20 minutes to be served water and an additional 30 minutes to receive our drink orders. Once we received our orders, several dishes were prepared incorrectly and the server proceeded to blame us for ordering the wrong dishes, etc. (when this was not the case!). In the end, the dishes were re-prepared but not without some hostility and resistance from the waiter. I found this surprising as we were a large party (willing to leave a generous tip!) but the waiter did not seem to care.
Food and Drink: Food was OK. I wouldn't say it's the best Thai food I've ever had but not the worst. I ordered the Pad Thai (a staple and what I would say is the "stamp" of any Thai restaurant) - the noodles arrived clumped together as if the dish had been sitting for a while. Flavours were marginal at best and the presentation was slightly sloppy.
Overall impression: Unfortunately, I wouldn't return to Bangkok Garden; there are far better (and less expensive) options in the Toronto area.