TX is awesome for removing a lot of the tedious work involved with traditional ETL, but there are still some things it can improve upon.... for instance, multi-select of fields in various cases would help speed up development a great deal.
The following are a couple of enhancements I'd like to see:
1.) If I add a bunch of Surrogate Key lookups to a table, they all end up at the bottom. I prefer that all the Keys are at the top of the table, so I then have to drag each one up individually. A multi-select capability for re-ordering would be incredibly useful
2.) Multiselect tables added to the Business Unit or Data Warehouse and drag them to reorder all at once. This would make things much easier with a project that has many tables!
3.) Multi-select fields in table #1 and drag into table #2 to create multiple lookups at once. This one isn't as big of a deal, but would help save clicks.
I think there are probably more places where multi-select makes a lot of sense. I'll add more to this post as I come across them.