I did manage to read through your entire post ;-)
Sony 505
I can't fathom why would a company stop manufacturing their best selling device. Excellent hardware, full-metal-jacket body, great display, extremely stable (if not very feature rich) firmware. There is a good reason why those devices fetch such high prices on second-hand market.
There is also very active hacking community with important improvements.
Cons are: non-user-replaceable battery, the firmware lacks some important features, like support for non-latin1 characters, folders, ...
Cooler.
I personally would not buy one of those. Especially if I was planning to take it on a 6 month trip without possibility to return the device.
Its hardware is manufactured by Netronix.
Other companies that use almost identical hardware (also made by Netronix) are Bookeen with their Cybook device, PocketBook and others. See our Wiki (link at the top) for more details.
I personally would recommend PocketBook 360.
Pros: It is very well designed hardwarewise, it has great lid protecting the screen, it has extremely feature rich firmware. It supports unprecedented level of customization, third party applications, reads most of the popular e-book formats (so no conversion is necessary). The only notable e-book format it does not support is .lit.
Cons: Some not very technically skilled people might be uncomfortable with the number of options and features it offers. Price. When it came out, it was priced a little bit more than some of its direct competitors, but now, when there is $150 Nook available ...
BeBook and other rebranded devices made by Jinke.
Not bad, IMHO. Again, see our wiki.
https://wiki.mobileread.com/wiki/Hanl..._OEM_customers
I was able to play with Hanlin V5. I found User Interface in firmware a little bit awkward, but apart from that it is a nice little device. Big plus is, it supports OpenInkpot open-source firmware. I almost purchased one because of that - it was before I "discovered" PocketBook
PDF.
Pdf files are NOT a good choice for an e-ink reader with 6" screen.
You can make pdf file that is formatted specifically for 6" screen (90x115mm (considering status bar)), but most of pdf files out there are formatted for A4, or letter or to be printed and cropped to the book format.
Pdf is a layout preservation program perfect for printing the document, or viewing it on at least 17" monitor. A 17" monitor has more than TEN TIMES bigger viewing area than 6" device!
Calibre does remarkable job converting plain-text pdf files. The best job I have ever seen in such converter. Yet, it is not good enough for my reading. You see, it *has* to guess where the end of the paragraph is, because most of pdf files do not contain such information. Pdf file contains only info needed to place specific character or piece of graphics on a specific position on the page. It has no info about paragraphs, formatting, chapters, ...
If I need to read a document that is only available as pdf I usually run it through an OCR program. I use Readiris, because I have a legal copy but FineReader works very well too.
Calibre.
Calibre converts almost any format to almost any format. It also makes its private copy of your books (it does not touch your original you have stored in your system of folders) and places it to its own Library directory. Beside converting you can assign various metadata to your e-books and have Calibre sort, sift, search, arrange, manage handle and present your collection. You can even browse covers in a beautiful 3D "cover flip" animation. It can also fetch metadata for your e-book from the net automatically. Calibre can also fetch your favorite news or blog from the net and format it for you seamlessly using so-called recipes. Unfortunately it can not cook a dinner for you. Yet.
Ha! Revenge!
Now YOU have to read MY long post
