I always find this line confusing.
"Most of the time he's amazing"
You wouldn't put up with that in any other situation.
"I love bacon. It tastes gorgeous but every other time I eat it I vomit"
"These flowers smell lush, except for Tuesdays where they stink of poo"
"I get the train all the time, it's brilliant, except for all the times it doesn't show up"
You'd stop eating bacon, or buying those flowers, or getting the bloody train.
My DP is amazing. Not some of the time, not most of the time, all the time. Yes, sometimes we argue, sometimes she upsets me and vice versa. But when it happens we talk about it like adults, compromise when needed and make up. That's how an amazing person deals with conflict.
Nobody should settle for "amazing" some of the time. I'd rather live without flowers than have my house stink of shit once a week.