For example, I found that removing some of the extra «hidden information» in one or two extremely sluggish PDFs with adobe acrobat pro greatly improved the speed of page turns — nearly as fast as normal EPUBs even with text reflow turned on. (blog.the-ebook-reader.com)
The biggest disappointment for me is the browsing experience, whilst WP7's browser is based on Internet Explorer 7 and its rendering is pretty speedy the lack of text reflow means on a small screen you will be doing plenty of panning around with a touch of zooming in and out. (carrypad.com)