krazo
phoenixrulzz
I think OG has very few 700 level questions. Many suggest solving verbal from here(GmatClub)...
Ya it is too bad that the OG does not provide difficulty level.
Are there many 700-level questions in the 1000 RC document?
1000 docs are illegal documents and should not be discussed here. Please respect the GMAC authority.
If you are looking for hard RC, try LSAT RC and CR. If you are able to crack them , gmat RC will be a cake walk for you.
Regarding the revision of OG' it all depends upon the time you have for the preparation. If I were you, I would have revised all the passages marked by me as 'difficult' and the last 50-60 questions.
There are Gmatclub's Guides to OG's with the difficulty level. Search them and it will be of great help.