We hit up the dog park a few times a week. Love it, it works out great for us. Jackson always has a great time. We do go on the small dog side 99% of the time. The only time I let him on the bigger side is when nobody else is there, or I'm meeting a relative/friend who has a big dog and it's just us.
We have 2 dog parks that we frequent so we start to see the same people and same dogs, around the same days/times, you learn who to avoid, and when you WANT to be there, etc. I LOVE it and Jax has an absolute blast.
We like people parks too. Sometimes it's nice to go for a long leashed walk and just mind our own business.
Here was us last spring at the dog park...