Pros:
History, mountainous surroundings, variety of challenges.
Cons:
Tough to follow for visitors.
Other Thoughts:
Oak Grove is where it all started, and I had to make a trip out there during my second trip to SoCal. Time well spent; while certainly not the best course I've played, and far from the prettiest, it was fairly distinguished and did require the full range of disc golf skills (though people who can drive 350 feet plus will have little to do here).
In many ways, Oak Grove reminded me of my home course of Gillies Creek - no signs and a couple extra teepads make it hard to follow. In addition it is untamed; the city parks department obviously doesn't spend a lot of time maintaining this park. On the other hand, again like Gillies, Oak Grove has concrete teepads at every hole, features woods holes, open holes, one hole going downhill, a couple with thick, forboding rough, left fades, right fades, and one ugly but interesting hole featuring a long shot over a wide, steep, gravelly pit.
Oak Grove features variety and playability, like Gillies, which makes up for some of the other shortcomings.
Finally, Oak Grove is set right up against the mountains, and they offer several towering views as you work your way around the course. You should go out to Oak Grove if you get the chance - those of us from "Back East" should see where it all started and California natives can get a taste of the touch needed to excel on the courses more common "Back East."
Favorite Hole - #1 - only grassy hole on course also is more open than others, but requires negotiating a couple of big, beautiful oak trees.