Upgrading to YUI 2.5.0

I'm upgrading the site to use YUI 2.5.0 (the previous version was 2.4.1). I decided to do this because the new version has many more features in data tables, and much of the utility of the TreeTapper site comes from interaction with data tables. The process of upgrading isn't too bad: the only problem has been needing to either add a "?" at the end of datasource files and then using initialRequest, or at least setting initialRequest to "" rather than the new default of "null" [under 2.4.1,

this.myDataSource = new YAHOO.util.DataSource("templates/vocabtable_js.php? table=applicationkind");

worked, while under 2.5.0, it is transmitted as

[URL]/templates/vocabtable_js.php?table=applicationkindnull

which won't work. The solution is to do either

this.myDataSource = new YAHOO.util.DataSource("templates/vocabtable_js.php?");
[...]
this.myDataTable = new YAHOO.widget.DataTable( "applicationkind", myColumnDefs,this.myDataSource, {initialRequest:"table=applicationkind"});

or

this.myDataSource = new YAHOO.util.DataSource( "templates/vocabtable_js.php?table=applicationkind" );
[...]
this.myDataTable = new YAHOO.widget.DataTable("applicationkind", myColumnDefs,this.myDataSource, {initialRequest:""});

The first option seems better].

The new version also has parsers (perhaps they were there before, but I missed them) that allow text coming over XHR to be converted to numbers, allowing numerical sorting.

The new version has at least a couple of downsides. First, making the tables seems slower (see this discussion), which is a problem when you need big tables, as TreeTapper does, and column headers are now drawn separately, and it can take a long time (>5 seconds) for them to line up with the corresponding column in the table.