Yes we are to some extent early adopters and yes the technology is not yet mature.
Some of the e-books do indeed have more spelling and typesetting (if you can call them that) problems than paper books.
But that may be because e-books are probably still perceived (by the publishers) as newfangled gimmicks that allow them to make a quick but uncertain buck with a minimum of expense.
I have to admit that after 3 years of reading e-books I now take spelling mistakes and crazy paragraphs in my stride.
As for annotations, I would think that the majority of readers would not do annotations (though from this forum I am aware of many that do) so the problems with annotations would not be considered vital by the manufacturers either.
But it will get better. E-readers have evolved a lot in a short time.
In just 3-4 years we saw the introduction of touch screens, front-lit screens, higher resolution screens, easy access SD-card slots and better looking eInk screens with all major manufacturers.
The e-readers are faster, cheaper, with more features, smaller (for the same size of screen).
Some features (notably sound support) have gone out and the bigger screens appear to have been dropped by the major players, these are probably due to low demand.
I for one am quite optimistic about the future. I'm now waiting for colour eInk...