Based on my experience, almost no one reads them. Every two years I put together a California voters guide and post it on Facebook for my friends. Many of my friends are very politically engaged, and even they have told me that they appreciate my effort because the don't have the time to do the research. I read the full text, I "follow the money", and I read the editorials from all the major papers in the state, if available, and then summarize that. Obviously I have a personal bias which shows through, but I try to use as much objective fact as possible.
It seems like most people don't get much further than the legislative analysis, if they even get past the headline. And the headlines have been getting worse every cycle. It's obvious that the people writing the propositions know that most people vote based on the title alone.
I'm the only person I know who reads the full text of every proposition.