⋯⋯X 是 X，就是/不过⋯⋯
解説
该结构用于先承认某事物的优点或特点，然后转折指出其缺点或不足。'X是X'表示承认某个事实，'就是/不过'引出转折，说明缺点或限制。
This structure is used to first acknowledge an advantage or characteristic of something, then introduce a drawback or limitation through a contrast. 'X是X' confirms a fact, while '就是/不过' introduces the contrasting point about the disadvantage.
例文
这件衣服好看是好看，就是有点儿贵。
This dress is indeed beautiful, but it's a bit expensive.
坐公交车方便是方便，不过人太多了。
Taking the bus is convenient, but there are too many people.