This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
My wild guess is that for a non-trivial application, the performance difference between Struts 1 and 2 would be negligible. Struts at it's core is a front controller. The bulk of an application in code, memory use and processor time is going to be business logic and persistence. Presumably these loads would be the roughly the same if implemented in either Struts 1 and 2. A bare-bones framework like FrontMan may be faster than Struts at some tasks, but for non-trivial applications, you'll probably end up reimplementing a great deal of what is already written, tested and freely available in Struts.