Danny Roth has a great approach, one that I've not seen any author use, and is only found in Fred Gitelmans Bridge Master software.
When a problem is presented, the author doesn't tip you off and say "what do you do on trick 3?
Instead the cards will be played, and at some point you will be asked to make a decision or make a plan. You wont be guided that "this is the crucial trick". For example on trick 2 you are asked to make a plan. In the answer the author shows that unless you unblocked/signalled yoru plan will fail.
Most of the problems are good. Not simple, but not involving advanced technique either. You need to count and visualize.
The negatives are the bidding is not 5 card majors USA style. Since teh author is British thats no surprise, but it made it hard to count or draw inferences on a few hands. Also, a few hands I thought the problems were not so good, kind of far fetched, or the bidding stupid.
You still get 45-50 good problems.
Worth the price

Second hand with dust jacket