Timmons is currently closed. We had a massive flood a couple of weeks ago that destroyed the bridges on the course. In addition to the course being unsafe, we're pulling the baskets and making some changes to the course while the city rebuilds the bridges.
Haven't been out to Easley in a while, but that course gets very little support from the city and often has some maintenance issues.
The two best in the upstate area are Central near Clemson and Shoally Creek/Va-Du-Mar in Spartanburg. Either of those are worth playing if you're driving past. I'd prefer either of them over Richmond Hills.
Grand Central Station is awesome. The best course in the upstate, and probably the second best one I've played in South Carolina (out of 48), right behind Stoney Hill.
As for Foothills, played it in May, and that course has been seriously neglected. All the money went into new ball fields, at the expense of the disc golf course. The best hole on the course - #6 - was ruined due to the work on the ball fields. I loved it when I first played it several years ago. Now, after playing it in May, I doubt I'll play it again in its current layout.