Also, consider the target audience. The review should address engineering students, perhaps undergraduates. Maybe mention how the manual is used in courses, for homework help, or exam preparation.
I should also touch on the importance of self-assessment. A good solutions manual allows students to check their work independently. If Riley's manual makes that process straightforward, that's a strong point. Maybe mention how understanding mistakes is facilitated by clear solutions.
Also, consider the feedback from other students or instructors. If the manual is highly recommended in academic circles, that's a strong endorsement. Or if there are common complaints, like too brief explanations.