I was in a Cancer/Leo relationship for 3 years.
Things went well for awhile but they got old. I always missed him and had him in mind, where he rarely thought about me and was more absorbed in himself and his thoughts and other aspects of his life. He needed his alone time and I wanted to spend all my time at his place, even if we were just sitting around watching TV.
We both got really annoyed with each other and fought often.
We're obviously not together anymore, but we're still close friends and really value each other.
I'm sure it could work, but it might not be easy all the time.
There were a lot of "Really? How could you think that way?" questions and we sometimes just didn't understand each other at all. But like I said, we really care about each other and I don't regret our relationship in the slightest.