Re: parameters in XSLT 2.0

The effect of using "as" on performance may be positive or negative. It may
cause the system to do run-time checks that would otherwise not be
performed. On the other hand, it gives the system compile-time information
that may be useful to perform optimizations. I would use it as widely as
possible because it speeds the development cycle and catches bugs more
efficiently, and not worry too much about any effect on performance.