Is typical ebook reader with pdf support enough to read scientific papers I am considering buying either an e-book reader or a full tablet. My main motivation is to read books and scientific papers and I really don't need all the extra stuff tablets can give me. 

My only concerns are 


whether e-book reader (that has pdf support) will handle many different layouts used in articles (how well will 2-column A4 page fit in an 800x600 e-ink display)
whether it will display math properly


Do you have any thoughts and (more preferably) experience about this?
No. Not sufficient. Kindle DX, an almost full-sized page, was not big enough. Refresh rates are not fast enough for flipping back and forth. Zooming interface is terrible. E readers are good for simple flow text, one page after the next. That is not how I read papers. Tablets do much better.