I've had Douglas system in i few theatres I've worked in and unless you get into a HUGE system you won't have any problems. Even the huge systems you will only have a problem occasionally after the system goes out of warranty.
I've had a few GE systems and the relays were not very good. Douglas has great relays. Their relays will force on or force off, meaning if someone does something to a relay, when you command them ON they will all try to turn ON, not just flip state.
Their controllers are very flexible too. They can accept just about any signal from just about anyone. Talk with the engineers at Douglas... they'll make the system that does exactly what you need. You can also add AMX devices for AV control and Pathway Connectivity devices for theatre and DMX control.
The last system I worked on had about 500 20A 2P and 20A 1P relays controlled individually from a DMX controller and about 50 circuits, both 120V and 277V, for work lighting controlled from ~20 stations. All of these could be controlled from the AMX system or the DMX lighting control system. The pushbutton stations also update with their status. At a master station if any zone or zones is turned on locally, the local switch and master switch will indicate that a zone is on or off.
It's hard to loose with Douglas, in my humble opinion...
Talk directly to the Douglas engineers for your design.
[This message has been edited by Mike Wescoatt (edited 09-25-2006).]