Reddit reviews The Land Between: A History of Slovenia

This is a short, well written article (albeit old and not completely on topic for your question) that should give you a general idea why Slovenia is better off.

If you are looking to get an even more in depth understanding, than best way to do that would be by reading a book about history of Slovenia. You have to know the past to understand the present. :) This is a book on Slovene history that I am familiar with. Unfortunately I don't know of anymore English books that would give you a more comprehensive answer to your question.

I don't think there's many books of all of our history in English. [This one] (https://www.amazon.com/Land-Between-History-Slovenia/dp/3631628773) is the only one I could find. I can't tell you wether it's good or not but it's pretty much the only one.