Hello Lakotahokie,
I'm unsure of which product you refer to when you say "caulk-like plaster filler" so sorry if this is way off base.
I would make the decision based upon how it is attached to the undamaged drywall around the patch. Since it is on a ceiling you need to take into consideration how it will be attached. When repairing a wall, no matter the method used, the patch is always supported from beneath by either the undamaged portion of the wall or the floor. With a ceiling your patch must be attached from above.
As a tile contractor one thing remains absolutely true no matter the trade - gravity wins - always. With a supported wall patch this is less of a problem, the support is there. With a ceiling the durability is dependent upon how it is attached to the structure.
A drywall patch is screwed directly into additional studs or supports which are in turn attached to the structure similarly. Very durable.
The other I'm unsure of so you should find out how durable it would be when attached to the undamaged area and which method is used.
Hope that helps.
Roger
Tile and Stone Contractor
Fort Collins, CO
TileArtCenter.com