Thanks all for your replies
I thought for a while about it and came to coclusion that indeed kindle is superior ereader for books - mobi and azw. PDF and browser is just a bait if you are undecided, free 3G as well
However these addons could be usefull from time to time. I decided to wait for my new kindle whilst doing myself a christmas gift - a new shiny toy named iPad
I am using my iPad for a little time now for reading PDFs and it is a way better than Kindle for this task. The big difference is bookmarks and notes navigation. Well I do not read from top to end most of my PDFs, these are reference guides which needs to be easily opened in several locations at once.