its not bad.. I bring a broom with and sweep some areas up and walk around and pick up any rocks I find. It has some slight dips where car tires sit around the yellow lines that can upset a 1/10 in a hard turn and the sewer grates will flip just about any RC on it lid even though they don't look bad but there are only a few of those.

a couple friends used to head out there and set up a track of sorts using large cones and race around. on weekend afternoons its completely dead there. Heck last sunday I ran almost a gallon through the landmax there all the while changing setup to get it dialed the way I like.

I took This pic and this pic there too. you can see the surface in both those shots up close.