The three or four experiences I've had with them are similar to Eric's.
Adobe gyrates, asks me about things I don't understand, is slow as can be, then there's eventually as little text as in a couple of small pages.
Perhaps the geniuses who design these things could update or downgrade my computer (a small 7 year old) so it could benefit.
In the meantime, I remain puzzled - what is the good of them?