I visited North Park last fall with family while B was mountain biking in the area. The park is beautiful! B said the mountain biking trails were pretty good, though I can't speak to that from personal experience.
We checked out the North Park Boathouse and grabbed a bite and a drink at OTB (Over the Bar Bicycle Cafe). We walked through the park and played with our niece and nephew at one of the playgrounds. There were plenty of play areas for children and dogs, which I thought was lovely. Our niece and nephew had a blast, and we got to meet some cute puppies who were enjoying the park as well.
I haven't had much experience with North Park, but my time spent there was very nice. And based on that, I would definitely recommend this park.