Perfomance: 'conditional instruction' vs. 'multi temp

Hi everybody,

if a node is to be processed differently, depending on a certain
condition, there are two approaches.

Let's say, the condition is "existance of child x".


Approach 1: two templates with different matching XPaths

<template match="thenode[child::x]">
  b& do_this b&
</template>

<template match="thenode[not(child::x)]">
   b& do_that b&
</template>


Approach 2: one template with a conditional instruction

<template match="thenode">
  <xsl:choose>
  <xsl:when test="x">
    b& do_this b&
  </xsl:when>
  <xsl:otherwise>
    b& do_that b&
  </xsl:otherwise>
</xsl:choose>
</template>


I wonder, if one of these approaches is to be favoured?
Are there any severe implications on performance?
Any other advantages / disadvantages that speak in favour of approach 1
or approach 2?

I am curious to read your estimations,
Norbert