I don't know, maybe they've improved things since I used to ride the Purple, but there used to be massive cramming every morning during rush hour, and very often in the afternoon coming back home as well. Do you ride the part of the route that goes to York U? That's really the only excessively busy part at this point: from York to Richmond Hill Centre.
People would be left behind at each stop (ala TTC Yonge line) because there simply is not enough space on the bus, and I wrote to YRT numerous times to get them to throw in an empty bus from Richmond Hill Centre when they saw overcrowding, which they eventually started doing... But it was so inconsistent in execution that sometimes it worked, sometimes it was a waste.