I'd be against early access too.
I follow a couple of early access game on Steam, there are those that do it well like Prison Architect (which while well supported has been in Alpha a very long time and is admittedly heavy with bugs) but Next Car Game has had a poor update record while keeping followers of the project in the dark.
Personally I'd not even be keen to even see a playable demo before full release either. I'd be more inclined to see only short video clips via their Twitter feed etc showing a few gameplay mechanics and early areas as time wares on. I think they might go down this kind of route as the delayed reveal of the main characters is a similar tactic.
With early access comes more hype, but then also more pressure from people who want the game a) immediately and b) the way they want it. Even the threads on this forum about things you want and don't want in the game are heavily commented on. I'd be worried that in trying to please everyone, they don't actually get the core feel right and end up with a disjointed end experience.
As a previous poster said there are those out there who write off early accesses as being awful and thus give the game an unfair bad press to friends, via social media etc. Steam forums are pretty depressing in that regard.
"Shanley, do you think Donkey Kong Country revolutionised gaming?"
"Yeah mate, I think it probably did"