For a while I have been eying stand-alone eBook readers that use "electronic ink" displays, the most popular ones seem to be the Amazon Kindle readers.

My criteria are as follows: It should be able to display pdf's and math formulas in them just like they were printed and they should be able to handle "big files", say the numdam versions of EGA (even with my desktop browsing them is noticeably slower than browsing other pdf's). A nice but not strictly necessary feature would be the ability to read djvu files.

Does anyone here have experience with these kinds of devices? Does anyone use them in their mathematical work days? Do they make things easier?