I found Kaplan's method too time consuming as well. All I do is read through the whole passage as quickly as possible while retaining as much info as I can. Then, I just refer back to the passage for each question. This probably won't work well for very difficult passages where writing down key words and paragraph subjects would help. I think the RC is basically a coin toss... if you get lucky, you'll get three easy science-related passages (that you already have a background in) like I did. The passages and questions were so easy that one read-through was enough to answer most of the questions. If not, you'll get ridiculous passages about pianos with tone/inference questions. So I think the best way to go is play it by ear. If the passage starts to get difficult, start to write down notes to help you.