General GMAT Questions and Strategies | Re: Should we take GMAT Official Guides seriously ?

Hi all,
While preparing for the GMAT exam, I came across this argument on many posts and forums that GMAT OG questions are easier than the questions on the actual exam and hence students should vouch for more study materials.

I wanted to know as how valid this statement is? If this statement holds true, then which study material should we refer to in order to boost our preparation ?