Marplots, what is your opinion of Scientology?
I think it's a grand experiment in human behavior. I think the system itself is the driving force, beyond any specific "tech" on offer. In this light, it has the strengths and weaknesses of any collective, including the tendency to go all wacky without a mechanism that checks against other ideas.
If you mean the doctrine, I haven't seen anything other than bizarre ways of looking at the world. I don't see how they are very informative. But none of that means they have to be. Beyond the parallels with the Elks or the Boy Scouts (who, I gather, have just as nebulous goals), the organization preys on the better nature of those who buy into it and David Miscavage is riding the horse hard.
The thing that I don't yet know is how much choice is actually involved by the membership. Are they free beings choosing (as much as anyone chooses) to follow a strange hobby or are they puppets -- or some combination?
I also think they are vulnerable in one particular way. The rise of easily generated media, both books and visual media, steals away their power to impress with authority based on these items. Every YouTube video that shows some embarrassing element, every document and website that lays out the criticisms -- well, those taint what might otherwise seem pristine and worthwhile. I don't think the church can prevent this poisoning of the well (from their perspective). Society, at least in the US, is getting inoculated.