Club lounge breakfast does not equal to breakfast at restaurant. At least at Crown plaza Akita. The lounge breakfast is not where near the quality. However, Crowne plaza hiroshima lounge breakfast is okay just doesn't have morning steak that full restaurant offers.
It is a difficult call for those who have lounge access. I stayed in holiday inn resort karuizawa. The breakfast has negitoro, I ate a lot everyday. I do want to keep diamond if the cost is not too expensive even I travel as a solo.