Post scriptum 2: InterRail pass
There’s plenty of options in InterRail passes with validity ranging from just 10 days to a full month, some with fewer travel days than the actual validity period on calendar - and all can be purchased for either 1st or 2nd class. (And all are offered with different prices for young people, adults and seniors.)
I knew I was going to be on the road for almost exactly a month, but getting the full month InterRail pass would have been overkill as I wasn’t going to travel even nearly every day, and some of the shorter trips especially in Italy were going to be very cheap to purchase as regular tickets. So I opted for a pass that is valid for 22 consecutive days and allows traveling on 10 days from those 22. It gave the opportunity to travel on every other day on average, which seemed like a nice pace.
Based on couple of blog posts and articles I had read, I ended up choosing the 1st class version of the pass. It cost 200€ more than the 2nd class version (580€ vs 380€), but it was supposed to offer much more relaxed way of traveling.
Well, in my particular trip I probably would have been better of saving that 200€ difference and spending it on something else. I did quite many train rides on local/regional trains where there either aren’t 1st class cars in trains at all or the difference between the classes is very minimal. The longer distance trains like TGVs in France or Frecciarossas/-biancas in Italy then again are very comfortable already in 2nd class, so unless you are really traveling through the whole country on one ride (which I didn’t do) the additional comfort on 1st class might not be worth the price. And besides, you can always upgrade your individual trips on 2nd class InterRail pass to 1st class by paying the difference in price between the classes for that particular trip - handy way of paying for the extra comfort only when you really need it.
There’s one additional benefit for the 1st class ticket that can be really worth the money in busy travel months during summertime: there’s only a limited amount of seats reserved for travelers with InterRail pass on the long-distance trains, so if you’re not making the seat reservations well in advance you might not be able to get on the train you want. But as the 1st class IR passes are not as popular (and 1st class in general), you will have a much better chance of finding a seat on 1st class during those high-season months. But again, this was clearly not an issue during the spring months.
So even though I did enjoy some of the 1st class rides very much with complimentary proseccos, good air-conditioning, wide seats and good views I probably would have enjoyed the trip as a whole equally with the 2nd class InterRail pass too. But that’s just for this particular journey on low-season, where the distances traveled were quite short (max ca. 400km for one ride, max 6-7h on trains in total per day).