It's really good to get chance to review this book and it was really great experience to get something interesting stuff(called application performance) which is very useful for every liferay projects.
I am sure if you follow each steps which is mentioned in this book for your liferay application, your application performance would surely increased drastically.
I specially like some of the topics like Load Balancing and Clustering best practices, Caching practices, Load testing and performance tuning.
Even I tried to follow some of the mentioned steps practically and it was like a magic for me to see the Liferay application performance.
I would highly recommend this book to read as it has i would say tons of information which can be helpful to you to develop scalable application.Regards,
Sr. Software Consultant (Liferay,CMS,WCM)