My opinion is that everything I've read from Philip K Dick is annoying. It's not that he's a bad writer, just...annoying. I read A Scanner Darkly and didn't like it, but mostly because he captured the druggie mind set so perfectly that it was painful to read. I think he had very interesting plot concepts that lend themselves well to fantasy/sci-fi directors. Which I guess is supported by the pretty long list of films adapted from his books:
Total Recall
The Adjustment Bureau
Screamers
Radio Free Albemuth
Next
A Scanner Darkly
Paycheck
Minority Report
Imposter
Confessions d'un Barjo
Blade Runner