Tell me which one you have. How do they handle non-standard formatting, like pictures and tables?
I have the Kobo Aura One (largest screen on a fairly widely avaible e-reader). It displays pdf just fine, tables and all. But it is classic e-ink, just black and white, so pictures obviously suffer (they are generally distinguishable as it does something intelligent to do grey-scaling by portion of dots black:white), but there is a reason that I bought the Rigger book in the paper version.
PDF pages don't flip as quickly as something like a normal novel does, and very graphic heavy pages in particular can take several seconds, which is annoying (although quicker if flipping back and forth, I think it must save recently rendered pages in short term memory or something like that).
It includes a table of contents feature as well as basic search functionality. You can zoom in or out, but I find that having the whole page on the screen is readable so I don't generally play with that.
It is for sure NOT as good as having a book, and you are paying a substantial cost to get the e-reader, so not for everyone (I was going to get an e-reader anyway, after discovering that a lot of authors I like were publishing some material as e-books only, and that a lot of otherwise out of print books that I wanted to re-read were available electronically. And I can borrow e-books from my local library directly from the device), so paying a bit more to get the larger screen, and making pdf easier to read, was worth it to me.
(I took pictures of how it looks -- it is small and light enough that I tend to haul it around with me a lot -- but then found out that you can't attach files over 256kb to the forums, which wouldn't make very useful reference pictures. I'll see if I can pull them into google drive and set permissions so I can link you to them, later)
