Pro: close to city, short drive time, some nice trails
Summary: it is a nice trails near the city. However, compare to Bruce trails, you would bump into a lot of kids and families.
I am a regular hiker who hikes at many places in GTA. I like both urban hiking and rural hiking. We came here at end of August using free Park Bus (https://www.parkbus.ca/rouge).
The bus ride was free and pretty short compared to some other ride I took to a hiking spot. I still found the trails pretty interesting. Trails are mostly flat, not that challenging. At the time we came, there was no bugs. Most of the time, you walk along the river. I spent a least 3 hours hiking. The park was pretty big and you could hike here for a couple of days.
I think we might come back for fall colour as well. I high recommend this park for beginner hikers who does not drive far.