I have both the Problem Solver and Bentley's. I have found the bentley's manual more informative overall, than the Problem Solver. The Problem Solver has a lot of great info if you are driving a mid 80's or older 240, though it does have some early 740 info.

I have got some useful info on shortcuts from the Problem Solver, but would not purchase another one knowing what I know now. I would, however, suggest you strongly consider the purchase of the Bentley manual if you have a 240 series car.

The Volvo service manuals are helpful, but unlike the Bentely, you will have a series of volumes to collect.