[ViewtifulJon]

I'm looking to buy my first ereader device. I will be using it for reading/annotating university PDFs, as well as reading some standard fiction novels in English, Russian and Spanish. I have narrowed my consideration down to three devices (prices in USD):

-PocketBook Pro 902 @ $329.99

-Sony PRS-950 + case @ $247.95

-Nook STR + case @ $158.95

I like tinkering with my electronics, so I am comfortable installing PRS+ on the Sony or rooting the Nook Touch. Since Russian/Spanish support is pretty good on all 3 devices (only the Sony is currently missing Russian/English dictionary), the main factor causing my indecision at this point is PDF experience:

-For the PocketBook, I understand that larger screens are best for PDFs, but I'm not sure how convenient it would be to use the d-pad to put in notes/highlight passages etc.

-For the Sony, I hear the Sony readers have one of the best PDF functionality as far as software, but I'm not sure the price difference above the Nook justifies the extra 1 inch added to the screen.

-For the Nook, rooted Android essentially means the software/firmware side is taken care of, but I've heard bad things regarding a 6 inch screen for PDFs.

The only one I can test out locally is Nook STR as far as screen size goes (won't be testing actual Nook, since stock Nook firmware is terrible with PDFs, but I can test a similar device with same screen). I have considered and eventually rejected various other ereaders in my search (Kindle DX, Kobo Touch, etc.), so this is mostly the final step for me. If there is a model that you really strongly endorse however, I'd be happy to hear it. But given the information above, which would all of you pick if you were in my position?

...sorry for the wall of text