title_body: Kobo Aura One or the new 7 inch Kindle Oasis for PDF files? I have an old 2009 Kindle 4 with its low resolution screen. I work in academia so I read books, articles and technical documents in PDF format on a daily basis. I once tried to use my old Kindle for that but it caused more pain than it helped because the screen is too small, the resolution is too low and it is rather slow for zooming in and out. 
  
  I literally waited years for Amazon to release a bigger screen version (8" or more) of a Kindle but it seems that I could just die waiting for that to happen. Therefore I am in the hunt for something better than my 6" Kindle mainly for PDF purposes and the occasional MOBI/EPUB book. I considered the following options:
  
  
  The Sony DPT-RP1 would of course be anyone's first choice for such a purpose but I work under Linux and an old version of Mac OS X and the device is incompatible with these two systems. I also find the price to be a little exaggerated for what it really does (exclusively for PDF files). 
  The reMarkable 10" tablet seems promising but then there is that price tag on par with the Sony. What is more, I am really just interested in being able to read my books; I really do not need to be able to download and install new apps or take fancy handwritten notes. 
  The Kobo Aura One with its 7.8" screen has very good resolution. I want to believe that it might just be enough for my purposes on landscape mode. But I read reviews on how poorly it handles PDF files. Then I read about koReader OS which apparently handles PDF files much better than its original OS. 
  I also just read about the new 7 inch version of the Kindle Oasis. The screen is a little smaller than the Kobo Aura One's. But then I would tend to trust Kindle's OS a lot more because it has proven to be reliable. 
  
  
  Is the Kobo Aura One a good ebook reader for PDF files (under koReader)? Does the new 7" Kindle outperforms it? Or is there a better option on that price range (250 ± 50 USD)?
upvoted_answer: Ever since the time I originally asked this question, I have bought both a Sony DPT-RP1 and an old Kindle DX.
  
  The DPT-RP1 is really excellent. Thanks to its screen size, almost any conventional PDF book or article are perfectly readable.  But this has little to do with the answer. In fact I more recently bought an old Kindle DX because it was cheap and I wanted to try it. I am still amazed by how capable this old thing is. Its display quality is surprisingly good considering its age, and having a lower resolution than the DPT-RP1 has rarely been an issue.
  
  The Kindle DX has a 9.7 inch-screen so it is much smaller than that of the DPT-RP1. However, aside from some rare exceptions, almost all of my PDF books are perfectly readable on it. Issues arise when reading two-column formatted scientific papers where the font size is small and the original paper size is A4. These are the bane of the DX because you have to either read in landscape mode and constantly scroll using physical buttons; or zoom in and again, scroll up-down and right-left. So when most PDF files are formatted this way, indeed, as stated in a comment, the DX is "barely tolerable".
  
  I do not own a Kobo Aura One nor a Kindle Oasis, however, my experience with the DPT-RP1 and DX drive me to the conclusion that neither of those devices are good enough to deal with common PDF files because of their screen size.