Running ADP over the Internet will never be a miracle.  If you take a look
with the SQL-Server Profiler, probably that you will see a lot of redundant
requeryings; particularly when you want to update controls like comboboxes
located on a subforms.

Personally, I've seen a diminution of the number of requeries for the global
form when I directly change the RowSource of these controls instead of
simply requerying them.

Maybe using TS/Citrix will give you some break on that (but of course with
the limitations and cost$ of TS) but a much better solution would be to
rewrite your application using .NET WinForms or ASP.NET.

It's when you want to go over the Internet and that you see the great number
of useless requeryings done by ADP that you will see why Microsoft have made
the decision of slowly deprecating ADP in favor of .NET technologies.
However, a well designed ADP application developed by keeping an eye on the
SQL-Server Profiler will probably gives you an acceptable solution.