Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good, but...

While a fairly good overview of these 2 aircraft, the evaluation of their capabilities is more than a little "soviet" sounding. In other words these 2 development projects are described as the greatest things since sliced bread. A more objective and blunt account of their drawbacks would have made this a great book. With the extremely limited funding available and the isolated nature of these aircraft as weapons systems (as compared to the F22 which will be a fully integrated theatre weapon and probably the last US manned air superiority fighter) the compromises made by the Russian manufacturers are major and would be interesting to read about.