I have been riding the YRT for about 11 years now and I have seen the transition of implementing the VIVA into the transit system. I am quite impressed in the change, as the service was quite poor before technological changes such as ETA bus stops and the transit apps to inform riders of when to expect the next bus.
About 7 years ago I had multiple instances where I would be waiting for a bus for 30-40 minutes. That was ridiculous and really made me think twice about riding the YRT. As time passed the service continued to improve. Especially with the new VIVA buses which arrive more frequently than the regular YRT buses as they are on the high traffic routes. The VIVA buses are much larger and spacious compared to the YRT buses and the stops are at major intersections treating it as an express bus for the York Region transit line. I would recommend saving the environment and taking the York Region Transit.