Depends in part on what you're planning to do in that area. Near Socorro -- besides the old stuff directly in town -- are the VLA and Bosque del Apache NWR, among other things. Bosque will be very, very busy soon with the annual festival of the cranes, drawing thousands of visitors (and about a gazillion sandhill cranes, snow geese, and other migrants). The VLA is always fun anyway.
I won't bother with the county park. Casey's Socorro RV Park and Bosque Birdwatchers are the two that most visitors to the area stay at. Casey's is in town; Bosque Birdwatchers is actually in San Antonio just outside of the NWR boundaries. Both are pretty basic, especially Bosque Birdwatchers, but you're not there to enjoy the beauty of the park, but to enjoy the area. Check the dates on the festival, though, because you may be completely out of luck in the area, given the popularity of the festival.
http://www.friendsofthebosque.org/crane/:)
Lynn