I'm an American who studied abroad in France for a bit a decade ago and did a little traveling around Europe, including to Austria. The Austrian train system was the best by far even without Klimaticket. Specifically, you bought a ticket that entitled you to a set number of kilometers and you could use it any time in the month. Moreover, the trains actually ran on time and customer service was helpful. By comparison, under the French system, the trains were often late, the customer service was almost hostile, and your ticket was for a specific train and if you missed it for whatever reason you were out of luck.
This was a really big deal for me because the French government had just reneged on their commitment to pay my ~650 euro/month rent just a week or two before I arrived and consequently I chose to skip meals to save up a bit to make a couple of trips to Austria to Austria to visit my then-girlfriend-now-wife (I went from 175lbs to an unhealthy 140lbs over my 5-month stay).
As a parenthetical, when I was planning to fly to Austria from Paris, I put my luggage in a 24-hour locker in Gare du Nord the evening before the early-morning flight, but the room the locker was in was closed from 10pm to 6am and the flight left CDG at 7am, so I was devastated when I had to eat the cost of the flight ticket. I begged the staff to unlock the door for me in my best, most polite French, but they would invariably say "c'est impossible" (in my experience, this is what almost all French employees would say to any request which wasn't strictly in their job description, including asking for directions which made it all the more shocking when I would ask an Austrian employee in English for some help and they were positively eager to assist, even if their English was not very good).
