I prefer to connect over vpn/ssh to remote sites and run Flamerobin from my pc. I have all customer connections together, which is very convenient for me .
It's convenient, but Firebird (2.5 at least) is *very* slow over links with even modest latency. If I have something simple to do it's quicker to use ssh + isql than to connect with IBExpert or FlameRobin over the internet.
Hamish