I tested my application over internet and work slow but fine for me.
But
- I have internet dial up in client and Cable in server side.
- Used DSQL statment to load form info not use a Tables component like
TIBTable or TIBDataset, i think Zeos have the same slow components
because thay load a lot of data to work as BDE for old developers
- Also i cache all permanent info or cache the result for the same
request by my self, and make an age (10 seconds) for my info before
reRequest it again.

I think Firebird 2.0 have some improvements for slow connection.

In fact i prefer build a Web application using PHP for this case.