Shovit, you should keep in mind that you can have up to six questions with a reading comprehension passage and getting five questions on a passage is common. It is true that the Official Guide presents more questions for a particular passage than would be presented on the actual exam - what you will notice is that there are usually pairs of questions that ask nearly the same thing. One of the two is considered more difficult and this is one way that the test writers can control the difficulty level of a reading comprehension passage. This is something that helps a student to practice - they see the different ways something can be asked. I certainly do not agree with the idea that having several questions on a single passage somehow makes the OG less valuable.
And if someone has no need of any strategy, but just wants to practice passages. I would recommend LSAT passages as opposed to any other source. LSAT passages and questions are well-written and edited and are of the same quality as those on the GMAT. And a used copy of one of the 10 Official LSAT books can be had for less than $10.
Remember that the questions on the GMAT cost $2500 each to write (according to Business Week Magazine) and the ones that are selected for the OG 12 have been official questions that are now retired. Unofficial sources are simply not as well edited, that is the plain and simple fact. The reason that I recommend a RC strategy book such as MGMAT or our own Veritas book is not because I claim that the passages are better than those in the OG, but so that students can develop strategies. Otherwise, a student who only needs to practice should go straight to the source with official GMAT material. And then as I mentioned in the post above to get the long difficult passages that might appear on the GMAT, LSAT questions are the toughest, cheapest, best source.
Bottom Line: Most people are likely to need some help developing their approach to the GMAT Reading Comprehension. Even someone who gets 9 out of every 10 right still have some room for improvement!
