“Related Posts by Zemanta” vs. “WordPress Related Posts”

Hi, a question: “Related Posts by Zemanta” vs. “WordPress Related Posts”

“Related Posts” is the ‘most experimental but still stable’ version
“WordPress Related Posts” is the ‘more advanced’ and stable version based on “Related Posts”
“Related Posts by Zemanta” is the ‘pro-like’ version

The questions then is:
1. Define “pro-like”
2. Does “Related Posts by Zemanta” have the “more advanced” features from “WordPress Related Posts”?

Basically, what is the hierarchy of the three similar plugins? For example: Chrome mobile has Canary > Dev > Beta > Stable. From this order, it’s understandable which is which.

Based on the FAQ under “Related Posts by Zemanta”, it should be this?
Related Posts > WordPress Related Posts > Related Posts by Zemanta. Which would mean that “Related Posts by Zemanta” has all the non-advance and advance features of “WordPress Related Posts” but in a “pro-like” something (which again we don’t understand what’s “pro-like” in this case).

The only differences I see are:
1. “Related Posts by Zemanta” lacks “Two Columns” layout
2. “WordPress Related Posts” is more “pro-like” because the “Advanced Settings” is in a collapsible drop-down which contains the Themes and Layout settings (“Related Posts by Zemanta” being “pro-like” does not have this
3. “Related Posts by Zemanta” lacks “About related posts” and “FAQ” collapsible drop-down which is in “WordPress Related Posts” (thus making the latter more “pro-like” than the former)
4. “Related Posts by Zemanta” have a “Only show posts from the last XXX months” setting which “WordPress Related Posts” lacks.

It is… confusing. Don’t get me wrong… only found out “Related Posts by Zemanta” because of the failed upgrade in “WordPress Related Posts”. Does “pro-like” means, “stable-stable-stable”? Meaning, it won’t receive sudden new tech?

Thank you very much for the clarification.