It's a nice, serene area for a leisurely walk or a trail run. It's clean and has a nice open area. It's nothing too amazing, but it's a nice option to enjoy a nice day at. There is plenty of seating for picnics or bbqs and it is always nice enjoying the view of the lake. But You should know this is not a hiking trail just a trail around the lake.
There was a 5k/half/full marathon when I went to Quarry Lake. This made it a bit difficult to walk around. My dog also could not walk very far after a while as there were burs everywhere attaching to his paws. I'd pick a different place when bringing a dog. It was very nice otherwise.
My boyfriend and I use this park to walk our dog frequently. We live relatively close (about a 15 minute walk away). We walk through the Western Trail and Alameda Creek Trail to Shinn Pond. Dogs aren't allowed in the water, but Shinn Pond is a very popular spot for dog lovers to take their dogs swimming. Sadie loves to fetch her tennis ball in the pond. It takes about 2 hours for us to walk to Shinn Pond and back. There isn't much shade on the trail, so bring plenty of sunscreen. There's plenty of wild birds to see. The park is pretty crowded with all of the things to do. There's the beach for swimming and volleyball. They have BBQ picnic areas available. There's a lot of lakes to fish in and a few fish cleaning stations. Many people use the park to: exercise their dogs, walk, jog, and ride bikes. There's always plenty to do here :)