It depends on how it's handled. I can't seem to write him with anyone else, because Ran is too major of a part of his life to be simply brushed aside without massive turmoil that I think needs to be addressed in a fic.

Ergo, is INCREDIBLY hard for me to write.

Other people writing it? Yay. I have a hard time seeing Kaito/Shin'ichi, but seriously love me some Heiji/Shin'ichi.