When I had a 'France Rail' pass a few years ago it was great. One word of note though. Those passes have a lot of fine print which many people don't read. At the time you were required to buy a reservation before boarding a TGV train but not other trains. It was not expensive but if you didn't have it and you were forced to buy it on-board it was quite expensive. Also having a reservation doesn't mean having a seat. Or it didn't at that time. Fortunately there were half a dozen of us without seats so we sat between cars and had a little party.

Jude