Can't say about readMe, but I found 2 column, near A4 size PDFs pretty good in Goodreader.
A bit too small in portrait, but fine in landscape orientation. Zoom in to get rid of the margins, hit the icon to turn off the horizontal scrolling and you're good to go. The scrolling up in down is a bit of a pain, but not too bad since it's so fast and smooth to scroll on the ipad vs. a pc/laptop or slow e-ink device like the Kindle DX.
I'd think any PDF reader would be the same for reading them as they should all allow portrait or landscape reading, pinch zooming etc.