First or Second Class on Warsaw to Krakow trains.

This might help (page down to the section "Warsaw to Krakow by EIP train...")

https://www.seat61.com/Poland.htm

I did not take this train - but I took some of the older TLK trains between Gdansk, Wroclaw, and Krakow back in 2012. I hope the trains have been upgraded overall in Poland, but it sounds like the trains between Warsaw and Krakow are newer than the others. Even so, I found that Poland was the only place I've ever found it worthwhile to upgrade to first class. On those old TLK trains, 2nd class was like 3rd class, and 1st class was like 2nd class in other countries. And 1st class didn't cost much more.

Nope, no need to go First Class. This particular route has nice high-speed trains.

Rode that train from Krakow to Warsaw in July. Very nice, modern trains. I can't imagine a need to pay extra for first class.

We got seats in the "Quiet Zone" car. It was pretty much silent the whole way. I liked it!

We travelled this route in first class last month. More legroom, if that matters to you, and they served a light meal - on real china! No plastic plates or cutlery.

The last time I took a TLK train was in 2005 from Poznan to Torun, naturally in second class.

It's not a very long trip, and I went 2nd class and found it to be a very nice experience--comfy seats and they served complimentary coffee and tea as well.

Thank you everyone for your help

We went 2nd class and thought it was very nice. We were there in July and had bought tickets on line. Trains do sell out or you may have to stand in a long line. I recommend buying your tickets on line.