Of course I won't be able to 100% know until it's actually released, but as of right now I think I am going to prefer the train more than the boat in PH.
I didn't particularly hate it in PH, but it wasn't a different experience compared to that of WW. It was refined in a way I suppose in terms of control, but I think it was a bit of a step down. I really enjoyed the wind / sail aspect of WW (although I know a lot didn't...) and I felt the simple drawing of the line and going got a little tired after it's novelty wore off. In the end, it was just sailing, which we'd done before.
I know the train will be on rails, and I know it will still be point A to point B choosing like the PH boat was, but it's a new enough gimmick to get me interested. Couple this with the fact that I loved trains as a child (and still do to an extent) and it seems like a win / win situation to me.
Also, now with the confirmation of track building, it's level of interest just went up a bit. I don't expect a SimCity like level of customization of pathways, but some additional customization like this sounds like an improvement over the boat for me.
Oddly, I would actually rather be limited in my travels to the rails rather than find myself not able to go further because of mysterious fog. If the designers don't want me to go to places I shouldn't be able to reach yet, they should come up with a better decison than that or square maps. A lack of track to get there suits me fine.
(hmm... in the end it really sounds like I disliked the PH boat even though I said I really didn't... Maybe I did more than I thought!)