I have brought my 1993 S10 in for work a couple times over the last few years. The service advisors have proven very knowledgeable and fixed the problems right the first time. For example, the last problem I had was with the truck not starting consistently and the engine would just kept turning over. When I replaced the battery and it kept happening sporadically, I thought it was the alternator. After I described the symptoms the sevice advisor thought a valve in the engine needing replacing, ran the test, replaced the valve, and the truck runs fine again.
My only reservation is that they seem somewhat pricey on service. Both times the actual bill has been above the estimate, and the estimate seemed high to begin with. Admittedly, however, I haven't shopped around on service prices so they could just be charging the going rate.