I've always wondered, was Hubbard 'enlightened'? Is that actually what Scientology is selling - behind all the hideous 3rd-rate sci-fi mumbo jumbo?
I have no doubt that Hubbard was fairly highly realized, he was an initiated member of various occult lodges such as the AMORC (Ancient Mystical Order of the Rose & Cross) and the OTO (Ordo Templi Orientis), and was actually accused by the former of stealing material which was later incorporated into Scientology. He was also connected to a guy called Jack Parsons, a high initiate of the OTO, with whom he conducted an infamous ritual in the late-40's called "The Babylon Working".
In my opinion, he was, in terms of the Western magickal grades he'd have worked with, an Adeptus Exemptus (7=4) and, to me, his development of the cosmology involved in Scientology was his attempt to carry out the task of this grade. Hubbard was batshit crazy long before Scientology came about though, but I'm fairly certain that his decline from the 1950's onwards was due to quite a specific aspect of the magickal process which he failed to do correctly.
Also, the practices detailed in the OT documents, to me, seem very much like a bastardized version of vipassana/bare awareness. I also suspect that his use of concepts like "Thetans" and all that stuff were actually his attempt to find a metaphor to explain Scientology according to his own semantic models, hence the sci-fi heavy symbolism influenced by his years of writing pulp fiction and sci-fi, but that, due to having become 'a black brother' (too complicated to go into here, google it and you should get an idea of where I'm coming from) he became deluded and started believing his own words as literal fact.
All in all though, the dude was a fucking headcase.

And while we're at it, are people like Eckhart Tolle's spontaneous awakening expereinces stream-entry? Or something 'more'?
I don't know whether or not Tolle's awakening was stream-entry, but I'm certain that, if it was, it didn't go any further than that. His own descriptions of how things were post-awakening do sound decidedly similar to how things were for me, at least for a few months, after stream-entry, but it's not hugely helpful trying to align other people's experiences in this way.