Performance of XSLT
One common critiscism of XSLT is its performance. The overhead of transformation from XML to another format is the price paid for clean separtion between data and programming logic, as well as the ability to customize transformations for different clients. There are some strategies for improving perfomance without giving up the benefits that XSLT offers.
The actual XSLT transformation is not always the root of performance problems. XML parsers have a significant impact on performance, along with many other factors such as database access time, time spent processing business logic, and network latency.
Obsessing over performance can be a dangerous trap to fasll into. Focusing too heavily on optimization techniques often results in code that is difficult or impossible to understand and maintain. From a strictly technique viewpoint, the fastest technology sounds great. From a business viewpoint, time to market and maintainablity are often more important that runtime performance metrics. An application that meets perfromance requirements and is easy to maintain over the years makes better business sense than a highly tuned, cryptic application that runs fast but cannot be modified because the original author quit the company and nobody can figure out the code.