Stylesheet to output XML Tags (node names)

I've made this little stylesheet to output XML Tags (node names). Is
it OK, from the point of view of functionality/performance?

I did noticed (or so it seems to me) that changing the select clauses to

*[generat-id(.)=generate-id(key('tags', name())]

will slow down the processing...



<?xml version='1.0' encoding='ISO-8859-1'?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
	<xsl:key name="tags" match="*" use="name()" />
	<xsl:template match="/">
		<nodetags>
			<xsl:apply-templates select="*[count(. | key('tags', name())[1]) = 1]"/>
		</nodetags>
	</xsl:template>
	<xsl:template match="*">
		<tag>
			<xsl:value-of select="name()" />
		</tag>
		<xsl:apply-templates select="*[count(. | key('tags', name())[1]) = 1]"/>
	</xsl:template>
</xsl:transform>