I use Oxygen XML for most of my XML/XSLT work, it auto completes the tags for you and when you edit the element name of a tag the end tags also changes. It makes XSLT's verboseness easier to work with.
I have noticed that PHP-xsl seems to ignore namespaces when I have had it declared in my XSLT template selectors. Works great for simple XML like you've seen in some of my classes.
I think of it as my XML scalpel to cut out only what I need.