Personally, I'm pleased that ePub gives pretty flexible (amorphous) layout. I fairly often change the font size on my eReader; making it bigger when I am tired, and make other changes such as minimizing borders. I'd much rather have that flexibility than a designer imposed view of exactly what the page should look like. That's why I hate pdf so much for anything other than its initial purpose of print preparation.
Of course, it depends on the purpose and details of the material. For example; the artist designed layout of large text children's books should probably be preserved ~~ but they aren't suitable for reading on an eReader anyway.