There's no nice way to say it. m2e sucks. If someone were to start a survey for the worst eclipse plugin, m2e would be the winner. anyone that actually wants to get work done should avoid m2e completely.
What a crock. Maybe you haven't used it recently, but m2e is currently working *extremely* well. It has no trouble handling our typical Java EE projects consisting of anywhere from 3 to 10+ modules. It's really nice being able to import projects and have everything "just work" with zero Eclipse (in our case RAD) configuration. Now that we use m2e, there's no need to keep Eclipse metadata in version control, so SVN stays nice and clean and our projects are OS and IDE agnostic. The POM is the single source of project configuration, which means that we don't have to keep duplicating stuff between the POM and Eclipse configuration.
If you want to use Maven and Eclipse, then you can't beat m2e. I'll grant you that it's taken a very long time to stabilize and become useful for more than just toy projects, but it's there now, so get over it. And, please don't suggest that the maven-eclipse-plugin is a viable alternative becaause that's just silly.