Epub is quicker, usually smaller and can be the basis for other conversions at a later date say for a Kindle etc.
Lrf is nicer to look on my PRS-300, but the look, becomes more or less invisible once the story 'takes hold' just like the Digitial Onscreen Graphics of Satelite TV etc.
Dodgy pages are often the result of older 'Rips' of books, often from scanning and conversion from PDF's. LRF's usually were the original 'bought' format so tend to be better formated.
I am an epub only user now.