The trains go most everywhere (not to Kazimierz Dolny) and places the trains don't go, the buses do. Since there is a lot of construction on the rail lines, it can be faster to take the bus, sometimes several hours quicker. While most trains are not the most modern, there are not without creature comforts. The express train to Krakow offers a small snack and a free drink (tea, water, coffee, juice, etc); however, it's only on the way from Warsaw to Krakow and not the other way around.
Warszawa Centralna, to me, is beautiful building. One of my favorites in Warszawa. It's imposing, reminiscent of a more communistic time. It's great, sweeping wings spread out majestically. Inside is a wide open hall, and underneath is a maze of tunnels leading to the tracks. It's really quite something. In the inner hall they even have a crackling intercom system that is just so… rustic. Most Poles hate it and most agree that it's hideous. I feel somehow drawn to it. Walking across that great inner hall always feels like an adventure. It's flanked by smaller stations which service region trains. I've never been in them.
On occasion, I can get lucky and sit in a empty compartment. Two benches to choose from, with enough room to mostly lie down. Other times, I'm stuck with a smoker. Traveling with different people in a compartment can be tough. In the summer, someone might close the window when you want to open it, and close it when you want it open (same with the door into the compartment.) In the winter, it can be worse. Women having hot flashes have no restraint in lowering the window to cool off, even though you are obviously shivering and suffering from hypothermia.
One good thing is that Poland does not have a high amount of fat people. You know those fat, hideous excuses for humanity that insist on taking up as much space as they can with their enormous, cellulite-filled asses? The ones with tits the size television sets and whose every breath sounds like a ratty, old refrigerator's compressor? Plus the random sounds that only a horse giving birth should make? Well, there are not a lot of them here, which is actually a great blessing.