On the subject of performance:
the performance of the framework itself, both in terms of CPU and memory consumption, is simply phenomenal. Performance matters.
On how Tapestry compares with the competition:
What I really like to give as an answer to people who ask why one should use Tapestry is this: because it is well-balanced and comprehensive. There are a lot of other web frameworks that are optimized with a certain thing in mind and in that narrow field, they typically beat the competition. It's difficult though to be a good all-around contender but that's exactly what Tapestry is all about.
On the effectiveness of Tapestry as a solution:
Today's Java is far from your grandfather's Java a few years back and Tapestry makes the best use of the more advanced, modern JVM techniques available today, such as bytecode manipulation, annotation-based meta programming and introspection without reflection. Tapestry code is purposefully remarkably succinct.
On how Tapestry enables modularity:
Perhaps we've gone a bit overboard with modularity, but since it's just that simple with Tapestry, most of our modules are independently usable but seamlessly work together in the same web application as soon as you add them to the classpath.
There's quite a bit more, and it is both favorable to Tapestry and well balanced. Read the full posting.