As filmmakers, still image transitions is not what we do, at least not very often. So my value assessment is derived from "real world" usability of this plug-in within the filmmaker space. Unless your cinematic production requires the futuristic feel that the transition Light Slice creates, the PulpFx Abstract plug-in is probably one that you can pass on.
But definitely keep a mental note about it because you just never know. If this plug-in was also able to handle video, we'd be having a different conversation.
Filmmaking is more about story telling and less about eye-candy. It's tough to imagine how the utility of this plug-in will enhance telling a story from a cinematic perspective. I hate giving lower ratings to good plug-ins. But, if you don't really need a wrench, no matter how good a wrench it is, it won't be particularly useful.