If someone just study Manhattan 9 guides and then practise 6 CAT of its is it enough to score 700 or official guides are must to solve with Manhattan 9 guides.
Have you taken any practice tests yet? If you're already scoring in the 600's, then it's possible that you have enough resources.
I suggest that you routinely take practice test throughout your prep. This will allow you to track your score trajectory and help gauge whether you need additional resources.
Cheers,
Brent
