Yes, the diamond will help you. Yup, chessmaster will also. I would suggest chess master honestly if you want to improve the most, but the diamond membership is more fun XD and heck the crown is nearly as good I think it is a better deal. I got this diamond for free lol
Diamond Membership vs. Chess Master?

could always get both, considering chessmaster is just about free at this pt.
EDIT: I think i paid about 6 bucks for mine and that was about a decade ago.

I am currently a member here at chess.com as well as at the internet chess club (ICC) and chessworld.net. Chess.com is by far the best option for learning at the current time. While I dont currently have the chessmaster software (or any other program), I assume it is similer to what it was. my conclusion: the features at chess.com -- particularly the chess mentor and tactics training features -- make it easily the best choice at this time.
As for chessmaster for $6, ebay is your friend
I would like to get the opinions of others who have used any editions of the Chess Master computer programs. I would also like to get the opionions of those who have used both, Chess Master, and Chess.com's Diamond Membership. My brothers and I are trying to get considerabley better at chess. I myself am rated 1216 USCF, and would like to get better. My two other younger brothers (ages 11 and 9) play only on chesskid.com and don't have USCF memberships. I have had a Diamond membership before and enjoyed it very much. I really like the unlimeted features such as, tactics trainor, and the videos library. So my main question is, when someone who is trying to get considerably better, how does chess.com/chesskid.com's memberships stack up against Chess Master when trying to get better for someone who's still young? Thanks.