performance issues and selecting

As a general rule, what is likely to be the performance difference 
between this:
<xsl:template match="cs:place">
  <xsl:param name="source"/>
  <xsl:apply-templates select="$source/mods:originInfo/mods:place |
                              
$source/mods:relatedItem/mods:originInfo/mods:place">
    <xsl:with-param name="prefix" select="@before"/>
    <xsl:with-param name="suffix" select="@after"/>
  </xsl:apply-templates>
</xsl:template>

.... and this:

<xsl:template match="cs:place">
  <xsl:param name="source"/>
  <xsl:apply-templates select="$source/descendant::mods:place">
    <xsl:with-param name="prefix" select="@before"/>
    <xsl:with-param name="suffix" select="@after"/>
  </xsl:apply-templates>
</xsl:template>

.... and splitting these into two separate templates each with a more 
specific match?  I notice my stylesheet has slowed down a bit, and want 
to understand the performance implications of what I'm doing before I 
go farther.
Bruce