We had two experiences with this organization:
1. We needed to use a specialty vet there (an animal eye specialist). She was okay and cured my dog's eye ulcer, but it was not cheap. However, the treatment involved some minor surgery on the eye which had to be repeated, so she did do quite a bit.
2. We were reluctant to use them when she was recommended because last summer another dog contracted a moderate fever. Instead of running blood tests and sending him home, they insisted on keeping him overnight and giving him IV, even when initial blood work showed no infection. We wound up paying over $1000 and the dog got better on his own within 24 hours. Plus they gave us a hard time about releasing him the next morning to go to his regular vet because the appointment was not until 2. But when we picked him up, he was already better and there would have been no danger taking him home - he was obviously not seriously ill at that point.
These people are not incompetent, but they are located in an area with lots of rich people just shell out dollars without questioning anything.
We have a regular vet (Bloor Animal Hospital) that is not 24 hour but has evening emergency service and you can leave your pet overnight if needed. Unless something happens at 2 AM, we will not visit this place for emergency service any longer.